I always love when I hear executives state the movies don't affect the comics or TV universes.
Case in point: Current Marvel Comics EIC Axel Alonso regularly states the movies don't affect the comics. We know that isn't true as Matt Fraction stated the Thor movie interfered with how he wrote his Thor comic; we know Abnett and Lanning were kicked off their Guardians of the Galaxy and Nova comics because of Gunn's film; we know the Inhumans are replacing the X-Men, and we know Marvel Comics cancelled the Fantastic Four because of the Fox movie. We also know the last ten or so years has seen Marvel Comics focus on the Avengers, and not the X-Men. And Steve Roger is returning as Captain America.
Regarding the DC Comics, legendary creator George Perez was pretty clear when he stated the Man of Steel people messed with his New 52 Superman comic, which is why he left.
And we also know the same happens with the DC TV universe.
Because of the Suicide Squad movie, Deadshot is "off the table," Harley Quinn was shelved, and with the recent death of Amanda Waller in Arrow, it's easy to guess the same thing happened with her character. Batman and Superman are also off limits for the Flash and Arrow universe, and Arrow couldn't use Blue Beetle, so they went with Atom instead. Now it's learned Deadstroke is also shelved (see below).
We can also speculate as a result of the new Green Lantern Corps movie, that now Green Lantern is also off limits.
There has been some online chatter amongst fans asking why this is the case -- as the DC execs regularly state the movie and TV universes are separate. Zack Snyder recently said more of the same. So why then can't they have the same characters? If I had to guess, my answer as to why the TV characters are being shelved is not to compete with their movie counterparts. We can probably thank Grant Gustin's Flash for that. I've said it before, I think DC has finally found their "Spider-Man" with Grant Gustin as Barry Allen and The Flash. The series is popular amongst casual fans, young fans, hard core fans and older fans (WB really needs to start heavily promoting Gustin and the series). I think WB is going to find it difficult to sell the Ezra Miller Flash to the fanbase. We see they have already started spinning that we should accept Miller because there are different universes. Ezra Miller has probably been coached on the topic as in interviews he's mentioned multiple realities/universes/dimensions. The controversy has even caused Grant Gustin to come out and tell fans that he supports Miller.
Now executive producer Marc Guggenheim is feeling the heat as fans asked and complained on Tumblr about the TV characters getting the axe, specifically the Arrow Suicide Squad characters with Deadshot, Deathstroke and Amanda Waller.
Fan #1: Any possible chance of either Slade or Walter returning throughout the rest of Season 4? #Arrow
MG: The character of Slade Wilson is currently tied up in another DC project. Walter is more likely.
Fan #2: You said that only Deadshot was off-limits, and Amanda Waller & Deathstroke are safe. But you guys killed Waller off just like that, and she doesn't seem like she will ever return(Because bullet to head). Who's next to be killed off? Katana? Once Deathstroke arrives in the DC movie, will he be also killed off too? This is really frustrating, that all awesome characters are being written off, because of the Suicide Squad movie, and is a slap to the face of Arrow fans.
MG: Um… I never said that.
Arrow's Stephen Amell, who may just be as frustrated as a lot of fans are (Amell has been vocal about wanting to be in Justice League with Gustin as the movie Flash), recently stated in an interview he thinks Arrow is missing Deathstroke.
"Manu [Bennett] is a character, and Manu played a great character. And I really honestly think that Arrow has been missing something since he hasn't been around. I really do. He was a transformative villain. I would really love it if Deathstroke could keep being a part of the Arrow universe," Amell said.
Sorry to say, Stephen, per Guggenheim's words, that isn't going to be the case. Let's just hope Green Arrow doesn't appear in the DCCU any time soon, eh?