Tuskarr would be neutral, not horde. Them being horde over alliance makes little sense. Both factions interacted with them in similar amounts in Wrath, so you’d have to forge a reason a la night borne for them to decide suddenly horde were a better fit. If anything the race they share the most with in an odd way is probably kul Tirans as they both have a form of spirituality that is very focused on the ocean and have lives that revolve around utilising the sea for bounty.
As for Vrykul as an alliance AR. Yes, I can imagine adding a third variant of human to a faction that complains about world of horse craft will go down exceptionally well if horde are given a totally unique looking race. We’re already seeing it with MGs and vulpera. It’d just further the arguments that horde ARs are more distinct than alliance ones and blizz thus favours horde.