Spoiler Alert! For those fans who watched season 4 already, we all know that Dr. Brenner was shot multiple times, and it’ll be surely accepted that he won't come back in the last season if season 5 focuses on the present. We also all know that Eddie Munson, who is portrayed by Joseph Quinn, will not return because of the sad ending in Season 4, but he spoiled us by saying that a cameo will not be out of the question, so we can hope that we will still see him for even just a second on the screen.
In an interview, Paul Reised, the actor of Dr. Owen, answered in an interview that he doesn’t know if he will still be included in the last season because, as far as he can remember, after Dr. Brenner was killed, the scene changed and he did not come back to the lab and proceeded to the destroyed Hawkins. The main villain that we all know, Jamie Campbell Bower, will still play Vecna, One, and Henry Creel, and he teased us that he knows something about Season 5, so we can expect to see his return in Stranger Things as the main antagonist of all time.