We’ll see. Placing Turalyon and Maiev in the Alliance drivers seats is a bad omen.
That being said there is a way to pull off an Alliance aggression story; have the Horde take their hits; give opportunities for Horde character building; and get us back in time for the “team-up” against the big bad. You’d just need to combined the SLs timeskip; the LIGHT cosmology enemy with Yrel and the Lightbound; and outright having the “Faction Conflict” occur before we get back. So we can skip right to the “hero” part. No PCs being forced into genocide paths.
The keys to this is having the peaceniks locked away in SLs; the Alliance Hawks only being prevented from wiping out the Horde due to fear of the cost to do so; and the fact that only the Horde knows the true nature of the Lightmother or Yrel. Where as the Alliance doesn’t. You could really do something neat there, with the Lightbound learning from the Iron Horde’s mistake and doing a subtle invasion. Using the Alliance Hawk’s aggression as a tool to do so.