I wouldnt be shocked if they just flat out removed those and made the other invasions randomized on a timer instead. Would probably be difficult to have an event in a zone with not just two variants, but one that changes based on a quest that not everyone has done, and which additionally forces Alliance players into a Horde form even if you have not started the quest.
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Just got mine half an hour ago or so. Definitely took a good few hour from when I accepted the reward to when I actually got it.