Overwatch PvE could make a comeback, but don’t expect another full campaign anytime soon.
Game director Aaron Keller says he wouldn't rule out bringing back playable story missions. However, Blizzard found that the previous PvE missions didn't keep players engaged as much as expected.
Keller admitted that the previous campaign generated excitement, but “it didn’t really get played the way that we wanted it to.”
Smaller PvE experiences could still return, but a full story-driven campaign would probably need a separate team and “a whole new game.”