I don't see Avery Brooks returning as Sisko on an animated comedy show of all things. No way in hell.
John de Lancie might be up for it, though. And Q might be a good fit for Lower Decks. Although I must say that his character (particularly as it was presented on Voyager) hasn't aged well. A lot of his “humor” stems from misogynistic jokes that weren't all that funny even back then.
Q cracking sexist jokes was such a dumb idea and a fundamental misunderstanding of the character. And it's like Q "knew" that Janeway was a character on a 20th Century show, since such jokes should just baffle a 24th Century person as being so out of date as to make no sense.
Voyager was just terribly written. Although "Death Wish" (the episode that contained said sexist jokes) was actually one of their only decent episodes, if you look past that initial stupidity.