According to an interview ComicBook.com performed with Safran, the notion of bringing Smith back as Deadshot was at least bandiered at a time.
“We discussed it,” he said, repeating that it was actually “more of a schedule than anything else” that prevented Smith from returning. “We knew we had to start shooting in September because we honestly probably knew earlier than other people that James would come back and do [Guardians of the Galaxy Vol. 3]”- a film that is currently in pre-production and scheduled to start filming in November 2021 by a release date in May 2023 according to Hollywood Reporter.
“So it was really important that we started shooting when we started shooting and Will was not available and that kind of made it easier everywhere,” Safran added. “What do you want to do? He’s not available. So it’s also nice to honestly help separate it from the first film, I think, in a bigger way.” To paraphrase, the omission of Deadshot was not necessarily a conscious creative choice, but may have yielded creative returns in service of Gunn’s interest in distinguishing “The Suicide Squad” from Ayer’s films.
While it’s a shame that Smith does not return in “The Suicide Squad,” the fact that Deadshot was not reworked means, at least, that the door remains open for his return in a later film. Judging by Safran’s recent comments, it remains a very real possibility.