Of the Netflix Marvel TV shows releasing from 2015-2019, Daredevil, by general consensus, was the standout winner. That's not because all the other shows were poor, but really because Daredevil proved a genuine gold mine. It was a complete 180-reversal of the critically-panned 2003 movie that beautifully revived the superhero in live-action. Even Season Two — the "black sheep" season — proved a generally-well-received run, but Season One and Season Three were masterclasses. That's why the show's cancellation shortly after three sunk many fans' hearts.
With some rumblings concerning murky-at-best details on when exactly Netflix's contract ends and allows Disney/Marvel to use the character again, fans desperately hope for resurrection, though it may not be how they want. Daredevil definitely proved it deserves a revival and to be part of the traditional MCU, but there are reasons in favor of that and reasons its return should avoid mainline MCU connections.
Return: Spider-Man
Perhaps the most tantalizing proposition of Daredevil returning to the mainline MCU — part of the overarching film/D+ series plotlines — is that Matt Murdock will be able to interact with other Marvel characters outside of his Defenders. Specifically, it opens up the door to have Daredevil & Spider-Man team-up.
In the comics, both superheroes are known to have a fan-favorite partnership/friendship in handling street-level affairs. Their dynamic is great to see there, including Chip Zdarsky's current Daredevil series, and seeing Tom Holland's Spidey and (ideally) Charlie Cox's Daredevil interact would be a dream come true.
Stay Out: Daredevil Thrives Outside Conventional MCU Stories
A point in favor of reviving Daredevil, but keeping him only loosely connected is that the show arguably thrived because it didn't need to worry about the greater universe. Until told otherwise, all the Netflix series are canon to the MCU, but only in passing reference acknowledge so. This was, particularly, Daredevil's strength as the creative liberties allowed on Netflix allowed for more grounded, smaller-scale, intimate stories and freeing from the shackles of the films' formula.
MCU has plenty of hits, but particularly with some solo-hero movies, they suffer from being overly-generic/formulaic, feeling like they have no compelling stakes knowing that this is all just setup for the next big crossover event, plus succumbing to one-note, shallow supervillains. Daredevil did incredibly well in exploiting the freedom Netflix offered, so retaining that same level of loose-connection could be best.
Return: The Multiverse
With DC excitedly looking to properly compete with Marvel theatrically and on TV with their big deep-dive into the multiverse with The Flash and their two Batmen, the MCU is setting up a cinematic multiverse as well, particularly with Doctor Strange in the Multiverse of Madness. On top of that, the trailer for WandaVision and Jamie Foxx's return as Electro in Spider-Man 3 hint at a multiverse playing with Spider-Men.
If true, it gives Daredevil an easy way back in the mainline MCU. They could simply explain the Netflix shows were all part of one universe in Marvel's greater cinematic multiverse. It could also be an excuse to execute/explain the show's loose connections or start a soft-reboot with the same core Daredevil cast.
Stay Out: Avoid Reboots
It may be best for Daredevil to be done while staying loosely connected, or even completely disconnected, from the overarching MCU in order to avoid any kind of reboot. This would be how a Daredevil return not being how fans would want it.
Understandably so, as Daredevil doesn't need one given its quality. Disney/Marvel could simply continue the show as normal — a literal season four — and explain that Daredevil takes place in the same canon as on Netflix, unaffected by the latter MCU events (Infinity War, Endgame, etc.).
Return: Soft-Reboots Could Work
Though, should a compromise at Disney and Marvel Studios work out well, a soft-reboot could potentially work. Daredevil could mostly continue as a soft-reboot if the same core cast is retained, Charlie Cox and Vincent D'Onofrio primarily, by having a successor series that avoid some complications of adhering to Netflix's show's events strictly.
This could arguably be done as, aside from the teased Bullseye return, everything ended in a clean, open-ended manner that doesn't force the characters' immediate futures in any specific direction.
Stay Out: Disney+
One of the limited possibilities of where Daredevil could find himself is on Disney+. With the many strengths of Daredevil on Netflix taken into account, ending up on Disney+ could be a problem. The reason for that being Disney+ is meant to — largely — be a family-friendly platform, and as fans know, Daredevil isn't "family friendly."
While being dark, gritty, and serious doesn't guarantee high quality, the way it was executed in Daredevil is among the major reasons it saw overall critical praise. Disney+ could force the creative team to water it down so much that ends up feeling like the weakest parts of some of the movies. Though, with The Mandalorian in mind, there's at least a chance Daredevil could still get justice done to him on the service.
Return: Hulu
But Disney+ isn't the only platform Daredevil could return on. Disney+ is also the (vast) majority-owner of Hulu, which isn't strictly tied down to being a heavily Disney-influenced platform in relation to types/genres of content available.
Hulu is being positioned by Disney from a marketing perspective as being the more mature-content oriented platform, serving as a complement to Disney+, not a replacement — hence the bundled packages of Disney+ and Hulu. Daredevil could potentially return unscathed on Hulu since it should allow similar creative freedoms to Netflix, allowing to fully "let the devil out." Plus, more adult-oriented Marvel shows are already set for Hulu.
Stay Out: Recasts
If things take a turn for the worst in reintroducing Daredevil and they go with a hard reboot/reset and not a soft one, recasts are a major fear. As touched on, fans recognize that reboots of any kind are unnecessary from a quality perspective, and that includes the actors involved.
Bringing in a totally different cast would likely be the biggest insult to fans. Charlie Cox and Vincent D'Onofrio especially established themselves as the Daredevil and Kingpin. Their performances were executed masterfully and both actors continually expressed their desire to return. Deborah Ann Woll and Elden Henson as Karen Page and Foggy Nelson are key as well since they also brought plenty of passion to their characters.
Return: More Revivals
If a Daredevil revival proves successful, returns of other familiar Netflix/Marvel faces could follow. The likes of Jessica Jones, Luke Cage, and Iron Fist could all see themselves get second lives, though Iron Fist would need heavy-duty rewriting given the original Iron Fist was critically panned in season one and mixed/lukewarm at best in two.
However, the biggest potential revival following Daredevil would be Punisher. The anti-hero was brilliantly portrayed in Daredevil season two and his own series, though his return would certainly require Hulu given the brutality of the character. It would be fantastic to see the both of them interact again, even more so than with his fellow Defenders.
Stay Out: Bullseye
As an extension of the risks for a revival through reboots, Wilson Bethel's Bullseye could be another sacrifice made whether the series gets a soft or hard reboot/reset. While it could be forgiven if fans still get to see the core cast from all three seasons return, missing out on that one loose end from season three would still be a disappointment.
Bethel gave a haunting, chilling performance as Bullseye and the prospect of him returning in a season four/five for a grudge match having fully-embraced individual agency as a supervillain, instead of a lapdog to the bigger supervillain and being disguised as Daredevil, would be thoroughly compelling given his new biological enhancements.