The CW president Mark Pedowitz says the network doesn't have any plans to add more DC Comic TV shows to their slate this year. Since the turn of the century, it seems that there has always been some sort of superhero TV show on the air (whether it was Smallville or Blade: The Series), but it wasn't until Arrow premiered in 2012, and Agents of S.H.I.E.L.D. premiered in 2013, that both DC Entertainment and Marvel TV started to expand their lineups.
Two years after Arrow's debut, The CW launched their first spinoff series, The Flash, starring Grant Gustin as the eponymous superhero. Then, the following year, they ordered DC's Legends of Tomorrow -- a team-up series consisting of heroes and villains from both shows that attempt to safeguard the timeline -- to series. The same year, CBS ordered Supergirl to series, starring Melissa Benoist as the famed Kryptonian; though when it came time to renew the show for a second season, the network decided to move the series over to The CW, a network they co-own with Warner Bros. TV. So far, that brings the channel to four superhero shows - not to mention they also have iZombie, technically another DC Comics-based series.
Needless to say, The CW's primetime lineup appears bloated with DC Comics-based superhero shows - and although they have already ordered Black Lightning to series (the network's fifth DC superhero TV show, but the first to exist outside of the Arrowverse), Pedowitz told the press during the network's summer TCA presentation that they are currently done adding superhero TV shows to their schedule:
"We have no plans to develop any DC shows this season. That said, I’ve now said this at many TCAs, and I woke up one day with Supergirl and I woke up one day with Black Lightning, so talk to me in May [about] what we have."
It's true, Pedowitz has said multiple times before that they had no plans on adding any more DC Comics superhero shows to their lineup, fearing that they would succumb to becoming the superhero-themed channel. By doing so, their Arrowverse would overshadow their other programs, such as The 100 and The Originals. Unfortunately, with Black Lightning joining the fold and Riverdale entering its second season, The CW now has seven comic book TV shows that air in primetime, roughly half their entire lineup -- including summer and midseason shows.
The network executive knows that things change, especially when new projects cross his desk, so it's understandable for him to be open about adding more projects down the line, and not completely shutting out that creative stream. If The CW does decide to pursue more DC Comics shows, the question will be, who will be headlining the series? The DC Universe is vast, and the network's Arrowverse continually populates its world each season, so there are many characters and stories to choose from.