Welll, honesty I don't care about superhero TV shows being part of a cinematic universe.
To me, for superheroes the best way is the movies. With TV shows you have cheaper special effects, cheaper actors, cheaper costumes, cheaper action scenes. The worst case is Smallville.
Seriously a TV show about Flash? He will never look as great as he could look in a movie.
The only way it's justified it's for street level characters, like but even so, it would be better for like 6-10 episodes miniseries (like Marvel's doing with the Defenders series), not 24-episodes seasons.
Why to introduce Green Arrow via a cheap TV show, and make him see "half decent" when you can wait a little so he can appear in a movie?
Also, as these series for being part of a Cinematic Universe will have to have some connections with the comics, they basically have to throw some characters there, but they can only use the B-lister or C-lister ones, those people don't care about, like Deathlok, Lorelerei, so the movies can still use the good ones.
Occasionally someone good as Deathstroke, but it still would look way better in a movie...
