The current societal climate dictates that the things that sell, nine times out of ten, are things that reflect, rather than ignore, said societal climate.
Is there a chance that Gunn's vision of Superman ends up bucking that trend? Sure.
I just don't think that chance is very high.
Okay, let's try to reason this out a different way.
The examples you posted were all TV shows, and of a specific genre for a mature audience. What about movies? Specifically big blockbuster action/adventure movies, like Superman: Legacy is aiming to be. What have been the most popular of these in the past decade or so?
Well, the MCU, obviously, comes to mind, and most of their characters at least try to be good people, even if some are flawed.
With DC, well, the Box Office king of DC is currently Aquaman, and while that particular version of Aquaman may be deeply flawed, the movie was all about him becoming a better version of himself.
The Jurassic World trilogy ... okay, characters didn't play any part in this particular franchise's popularity, but still, it's not like Chris Pratt's character would be considered an anti-hero by anybody.
Star Wars, well, those new movies lived mostly off of the brand recognition, but again, the hero characters were indeed heroic. The one that is even remotely debatable is Luke Skywalker in The Last Jedi, and I still hear people complaining about how that movie destroyed the character.
I mean, honestly, the one big tentpole franchise that actually has anti-heroes in the lead is the Fast & Furious franchise.