Well, Vader and the Emperor are dead, so we're definitely going to be seeing different big bads. Maybe at the head of a reborn and resurgent Empire?
Maybe the Empire has been relegated to a few small systems as part of peace treaties, and now the Republic needs new allies in the Imperial Remnant to take on the new bad guys?
Maybe the new Empire plays a very small role.
Lots of different options and we just don't know enough yet.