Well, as I said in the original post on this topic: there are no guarantees with content on the Public Test Realms.
In a post on the PTR Forum today, Blizzard poster Kisirani said:
The Sunreaver Dragonhawks that have been tamed will keep the coloration they have on live realms rather than getting a new texture.
In other words, taming a Sunreaver Dragonhawk now on the live realms will NOT get you a cool retired pet with a unique appearance.
If you tame a Sunreaver Dragonhawk now, or if you have tamed one in the past, you will not lose your dragonhawk — but it will continue to be a standard red dragonhawk even after the ‘wild’ version changes to the new mount-like appearance in Patch 3.2.
Kisirani also explained a bit about why this situation is different from other retired pets:
This is not a “grandfathered” situation as with other similar situations, as the new look for dragonhawks has not yet been live and this is a bug existing on the Test Realm alone. The new texture is being introduced in 3.2, but will now be applied to a new Sunreaver Dragonhawk that cannot be tamed.
Of course I’m sad about this — more pet appearances are always welcome — but I also understand their decision. … And at least this way the hated Alliance aren’t taming a beast that should be all rights be available to us Horde. *grin*
(My thanks to Beasthunter and Brio for bringing this to my attention.)