Regardless of what it looks like, brace yourself for a bunch of people yelling "OH MI GODS REHASH" if it looks too similar to the current Nagrand, or another bunch yelling "THEY RUINED NAGRAND OMG" if it looks too different. As far as I'm aware though, it should look quite similar to the current one, only without the floating pieces of land and a different layout. Nagrand wasn't that affected by the destruction of Draenor, so it really isn't unexpected to have it be similar.