I mean, it's not the strangest call they've ever made (looking at blood elves joining up with the Horde and playing nice with the Forsaken back in BC and the draenei retcon). One could finagle it into plausibility in a full-on Legion invasion, much like they did death knights (who were similarly few and elite before the Ebon Hold questline established how they could be mass-produced and constrained in power to be in-line with other players).