I think Episode VIII will be Legacy of the Force.

The question of who Rey’s parents are is something a lot of people were discussing after seeing the movie and I particularly like one of them (keeping it vague just in case it turns out true and anyone wants to go into Episode VIII with as little information / speculation possible) and that would be a fitting title.

It would also work for Episode IX as well and might possibly be better as a bookend and setting up the next trilogy.

I do like the “Knights of Ren” title though.