This is copium, there was no way those shit would be just "obvious choices for shipwrecked troops", especially with zandalari model like that, it was a blatantly hit for the next expansion.
The point of hints is that they are supposed to be small/little, and we SHOULD ignore majority of the stuff to find then or take meaning out of it. Yes the next expansion is more inclined to be about dragons because all the subtle hints and things we could make sense out of it.
It could be nothing and they could totally go for a tangent or double down to more cosmic bullshit, but its unlikely.
Like, being completely serious, wow don't have many loose ends to pull out an entire expansion, neither many stuff to create from zero or amazing writers. The options we have atm that are more likely to be explored knowing the state of the lore and game are:
1 - Dragons
2 - Yrel/light invasion
3 - More cosmic bs
4 - Underground war that is being hinted for years with the blingtron
6 - Azshara coming back
7- A completely new/never seen stuff
Im putting my money on dragon stuff. Especially after Danuser making shit up with the dragon lore recently, i bet my left hand he will "claim" dragon lore for his own now.