People are honestly freaking out a bit too much over this, it's more than likely a rushed change and a simple oversight on Blizzard's part. Here's what you can do:
* On PTR, paste the following 3 lines in game chat:
/script DEFAULT_CHAT_FRAME:AddMessage('Shift-Click to place in chat, Ctrl-Click to view on character: \124cff8000FF\124Hitem:34556:0:0:0:0:0:0:0\124h[Thunderheart Waistguard]\124h\124r');
/script DEFAULT_CHAT_FRAME:AddMessage('Shift-Click to place in chat, Ctrl-Click to view on character: \124cff8000FF\124Hitem:34444:0:0:0:0:0:0:0\124h[Thunderheart Wristguards]\124h\124r');
/script DEFAULT_CHAT_FRAME:AddMessage('Shift-Click to place in chat, Ctrl-Click to view on character: \124cff8000FF\124Hitem:34573:0:0:0:0:0:0:0\124h[Thunderheart Treads]\124h\124r');
This will pull up item links to the T6 belt, boots and bracers. Alt-click each one to lodge a suggestion or bug report stating why you think they should be reverted back to their former stats. You don't even need to have your character copied over if that's still buggy, you can do this on a level 1 alt.
Alternately, make a post in the PTR forums, those are actually monitored and read.