Yeah there was a video about that not too long ago, if they really want to tell the full expansion story, they need to do a much more massive rework of stuff. Currently it's still fucked.
I did the "new player experience" on alpha, basically the new starting area into BFA(the only expansion you can play if you're new) and then some of the new stuff(but got tired of questing and moved to another game). The new starting area is pretty cool and efficient and you get a lot more items than you do in the other places(blue gear, all slots covered, bigger better bags etc). Story however is that you're some sort of new recruit going to an island to train and your boat gets wrecked and you have to rescue people, nothing special.
Anyway once you're done, you go back to SW/Org, and as soon as you arrive, the King/Warchief somehow requires you, Newb McBoots to come because they have an important message about the war. And then it starts BFA, which already doesn't make any sense. Anyway BFA starts and you do the usual stuff and start questing and oh it's war and Nzoth and all that shit, then you finish the BFA leveling basically at the apex of the war with many threats foreshadowed and... you just kinda stop, go to some fancy death shit, during which you get to see the other faction's leaders just having a chat all chummy while raging at Sylvanas again(which if you're horde 5mins ago was personally giving your orders but now is the "bad guy"?).
Whole shit is absolute garbage story-wise. It's nice to see each zone full story and get somewhat of an idea of the expansion, but you basically stop before resolving anything at all in that expansion, which is completely pointless. In BC you'd basically do war preparations against the burning legion then leave, same for Legion, in wotlk you get to Icecrown and then say peace Arthas then 5mins later you see that the Lich King wasn't Arthas anyway and who's that bald toasty guy anyway. Don't know about Pandaria or WoD but I'm sure it's the same. It's just extremely disjointed shit the way it's done, the only redeeming part compared to current leveling is you get to do more zones in an expansion so there's some consistency in design(instead of doing a bit of panda and a bit of demons and so on).