Beautiful pictures, Kalli!
(One tiny correction... the orange skin is a gazelle skin, not talbuk.)
Sadly the skin changes are no indicator they'll soon be tameable. I just say that in case anyone saw it as a sign and got their hopes up prematurely. It was just a matter of adding the missing skins (i) in case they ever become tameable, (ii) for more variety, and (iii) because some of those skins are so lovely it was a crime they were never used

That and Noah was very kind to add them

Thunderstomp's new skin was another one in this new batch of colour changes, just like clefthooves, mana wyrms were in 4.0.6.
Cross fingers they will be tameable in the future, though. Rams (still a couple of missing colours there), talbuks and gazelles (I think now their original skin is only available on critters, must go check that up) seem to naturally group as horned, ovine-like ruminants, as would stags and shoveltusks as antlered, elk-like ruminants. But then they could probably very easily be grouped as one big family of "Bucks" or something. They're all related and would perform a very similar function in combat.