Checked out ZG on the PTR, there are even quests for these nameds. First entered with a group of randoms, however that one quickly fell apart as just being in the instance randomly crashes your client.
Florawing is a hive of wasps, and there are several offspring of Gahz'ranka in the waters below. I think I've seen all of the mobs for the Headhunter achievement.
Layout was altered, you can go left in the direction of Jin'do's corner, which is now inhabited by Zanzil. Several dire trolls are hanging at the walls, reminds me of cow quarters hanging in a slaughterhouse, also, an "undead" feeling.
Several new bridges between the 'outer ring' and the temple in the middle.
Jeklik and Mar'li plateaus are blocked off by rubble, I could feral charge a monkey to enter Jeklik's, the area still exists, but is completely empty. Venoxis and Mandokir are still/again at their old places.
Temple of Bethekk is guarded by a "Tiki-Lord", which has a bone-shield-esque buff that throws bones around, though the buff tooltip implies it might just be
popcorn. Down in the temple is a new priestess, again with noticable cat adds.
Didn't explore further since, as mentioned, the client kept crashing while inside the instance, at the end it was already crashing when trying to log into my character.