What Does This Mean For The Future?
So theory confirmed. Where next? Well, perhaps nowhere. The Watchers clearly aren't all that impressed with their Informant, leaving before he can finish all his stories, so in-universe it may be that (regardless of what part the Watchers have to play in the future) Lee simply isn't important in the grand scheme. He's there, but as a secondary concern, someone who can tip them off if some serious stuff goes down but hardly a keeper of the Holocron. Indeed, that Feige described Lee as "above and apart" from the rest of the action can be taken to suggest the Informant ultimately operates on a more meta-plane than those he's observing. These are just cameos, after all.
Creatively, maybe a thumbs up is the limit. If Marvel were ever going to tip the hat to the Watcher theory, Guardians 2 - the one with the most out-there concepts of any MCU film - is far and away the best movie to do it in; a continuity rejigging wink slots right alongside empaths and Living Planets, whereas it'd jar with the 1970s-style espionage The Winter Soldier or Iron Man 3's exploration of modern media-focused terrorism. Indeed, this idea's not likely to be used much in the future; when it comes to Earth-based adventures like Spider-Man: Homecoming or even tonally-different space-set adventures like Thor: Ragnarok, any Watcher appearance will pull you out of the movie more than seeing the incredibly recognizable Stan Lee already does. It'd be possible for Avengers: Infinity War or Guardians of the Galaxy Vol. 3 to incorporate the element, but even then it would be hard to make much more than a running joke, with little wider substantial purpose. And, with the theory approved, does much more really needs to be done?
That said, there is one feasible way that Lee could be given a little more importance. In that same interview quoted earlier, Feige made a rather strong point that none of the Watchers in the sequence are Uatu, a clarification that could be taken as needlessly pedantic but is more probably carefully sidestepping contradictions for if/when the character is introduced. If Uatu does turn up and play a substantive role, then it would be elegant to work Lee's cameo into that; both related to Earth, they're sure to have some crossed paths. It'd be a subtle using of the suitable movies to tell a little fan-focused story almost in the background (like how Thanos' rise is really more for the observant die-hards than the regular multiplex-goer).
Stan Lee may not be a Watcher but he is a Watcher Informant, which is more than close enough. The theory is confirmed with a bevy of evidence - the scene in the movie itself, the credits, and comments by the franchise's producer - which marks it as the biggest creator-confirmed fan speculation this side of Frozen/Tarzan. It may not have the actual weight that those initially theorizing would have wanted, but it's still a satisfying reveal and one that highlights how the MCU can balance multiple levels of emotion, seriousness and continuity (all within the same film no less).
One thing we can say with certainty is that we haven't seen the last of Stan Lee in the MCU. He's already filmed three future appearances - Spider-Man: Homecoming, Thor: Ragnarok (which were filmed concurrently with Doctor Strange and Vol. 2's) and Avengers: Infinity War - and it'd be crazy to not expect him in Black Panther and Ant-Man and the Wasp, so whether he's informing inter-galactic beings or being harassed in a shawarma joint, there's plenty more of Stan the Man to be enjoyed.
- Guardians of the Galaxy Vol. 2 (2017) release date: May 05, 2017
- Spider-Man: Homecoming (2017) release date: Jul 07, 2017
- Thor: Ragnarok (2017) release date: Nov 03, 2017
- Black Panther (2018) release date: Feb 16, 2018
- Avengers: Infinity War / The Avengers 3 (2018) release date: Apr 27, 2018
- Ant-Man & The Wasp (2018) release date: Jul 06, 2018
- Captain Marvel (2019) release date: Mar 08, 2019
- The Avengers 4 / Avengers: Endgame (2019) release date: Apr 26, 2019