As far as Gnolls joining the Alliance, this is something I’ve said for years, but I genuinely think you could introduce a LOT of much-needed humor to the Alliance.
Obviously, the events of the past few years would have put a strain on Stormwind’s resources. The Gnolls, who rely on raiding said resources, would likely also be feeling the pinch, particularly as the Alliance have become more and more unified and likely harder for Gnolls to just “steal supplies” from.
As such, I’d have one of the Gnoll leaders (maybe Hogger, maybe Meatball, maybe someone new) come forward and basically say “You humans so weak and stupid, we see you don’t have as much food for us to steal. So we help you because you do pathetic, so we can have more food to steal. We show you what REAL strong look like!”, while the Stormwind officers are just looking around like “Uhh… okay? I guess you can just… separate up and a few of you join some of the Alliance expeditions about to deploy?”
So throughout various Alliance settlements, you might seen the occasional Gnoll or two. Some might be completely conceited, convinced they are the mightiest hunters in existence, and that everyone else is stupid and primitive compared to their cutting-edge technology like “a sharp objected tied to a stick”.
Conversely, you might have others that, the moment ANYONE around them uses even the simplest form of magic – or even just actual technology – they run around manically screaming “WHAT IS THIS SORCERY?!? THE END IS NIGH, RUN FOR YOUR LIVES!!!”
I honestly fee like they could just be SO much fun. And like I said, I think would serve an important counter-balance to the Alliance, which does tend to feel a little too “serious” and plain-jane most of the time. I think having these stupid, aggressive little guys running around would be kind of endearing. Plus, let’s face it; the Alliance has way more interactions with Gnolls as a race. It might be fun seeing them “bury the hatchet” after all the years, even if they’re more of a “minor annoyance” to the citizens of Elwynn Forest these days than genuine threat.