Maybe, strategy has made quite a bit return the last years especially with the popularity of turn based i don't see a RTS happening but could be wrong.
Classic RPG formats as seen with Divinity also have made a return in case world building is more their thing, plenty of roads to take but indeed i don't see a MMO happening too much of a risk too large of an upfront investment needed. I mean if i look at crowfall now good intentions and all but it shows how complex a MMO really is.