IMO any race that can be mage should be able to be warlock (with draenei the obv exception, but hey, give a red skin tone option exclusive to warlock class and boom, there you go). Warlocks are just drawing magic from a different source.
I was actually hoping for this to, personally. I really don’t like any of the Alliance races for warlock except maybe worgen. Especially in the animation department, void/blood elf and DI/normal dwarf caster animations are just really bad and humans aren’t much better. The panda casting animations are pretty good.
Undead are def my fav for caster classes, but I would like to see warlock available for pandas.