MoP did indeed tease that, until Garrosh got his hands on the heart of Y'Shaarj. Remember when people went mental over "just" going to a (to us) unexplored continent, with no obvious villain glaring at us from the box? I'd bet these are the same that now cry how WoW has lost its touch etc.
Hmm, now I really want to see that kind of expansion... but nah, after the intro with Teldrassil and Lordaeron, BfA was relatively laid back, they wouldn't do the same thing again immediately.
I guess for that to happen again in that way, we'd have to go to a different planet, maybe another one that barely escaped the Legion's grasp, possibly due to Sargeras' imprisonment, or because they redirected the troops stationed there to Azeroth.
We'd be helping to rebuild, to reclaim, from the Legion, from the Void, and/or just that planet's native evil forces.
However, for that to happen, we kinda need a Void expansion inbetween, to reintroduce the cosmic scale.