Originally Posted by
Golden Yak
Farahlon has been hinted at in some of the garrison shipyard missions, but no word on whether or not we'll personally get to go there.
Gul'dan doesn't appear to die in any of the encounters next patch, as far as I can tell. There's definitely room for another tier of content, it depends on whether Blizzard wants to develop it or not, or focus on getting the next expansion out.
Perosnally, I'm hoping for a 3rd raid tier involving the Infinite Dragonflight and more alternate timeline shenanigans.