As far as just acceptance goes, Xayah doesn't really need to because it's already suggested that she's friends or otherwise has some relation with Wukong. Just being friends with someone isn't her goal. You can still have friends of your own kind but want to be part of something else.
This one irritates me right here. As far as I'm aware, there is nothing that links Wukong to Ahri, and I feel as if they only have each other listed as "friends" solely because they thought "We can't have her with zero friends or rivals, just put down the other animal person from Ionia there". All its done is spur a shitty ship.
Personally, I just think people aren't thinking enough about this or are reading too much into stuff that isn't there. I don't see any reason to believe Riot has any reason to change her drastically just because she has a new label. I don't even see how the League universe has changed with the introduction of Vastaya. It's like discovering a new, extremely rare animal in the wild: nothing about the world has physically changed, only our knowledge has. They even presented the vastaya to us in that exact way with Santangelo's research journal. I think if more people thought of it like that they'd be less worried about everybody's new status of being vastayan.
If she is Vastayan, it could change her quite a bit, whether it be her methods, motivation, origin, or likewise. I can't say much about the League universe, as the only lore I ever cared about were Summoners and Ahri's lore, but I would think it changes quite a bit. Nidalee is likely Vastayan as she changes shape like the merchant, possibly born from Vastayan and Human blood, albeit diluted. Rengar and Wukong are likely Vastayan now, being full on anthropomorphic animals like the otter people. There might be a tribe of Rengars now for all we know. Ahri might be a pure blooded Vastayan, no longer originating as a magically inclined fox. It might add a whole new faction to the world, if I'm perceiving Xayah's motivations right.
As far as Ahri's character and personality, I'm not sure I agree that leaving her vague is the best way to do it. While I can certainly see the appeal in leaving her to everyone's imaginations, I also think it's lazy writing that restricts her narrative potential. I'd rather have a character that's empathetic and relatable because they're written well rather than have a character that's relatable or endearing because I had to fill in their missing character. Having a defined character would open her up to actually having some good lore and story participation, whether that means she has her own stories or is interacting with other characters.
Ahri's character and personality could use something, I mentioned that in my previous post. However, I don't feel that she needs to be part of a grand, overarching plot be it a minor arc involving Ionians or something global. I personally like how she doesn't interact with other prominent characters or in a larger plot. At best, other characters would have fleeting encounters with "The Fox of the Forest". Maybe she does her best to help travelers gone astray, all from out of sight. Maybe she defends her home from dirty Noxians, using their life essence to fuel her humanity as she deems them unfit. Her interaction should be minimal. It's entirely possible to portray her struggles, personality, and overall character when she's all by her lonesome, or just ever so slightly out of sight.
A big issue with everyone having their own version of Ahri in their head is few people will be agreeable to any stories involving her that they put out that actually demonstrate her character at all (a thing that tends to happen when characters interact with each other).
Well, that's the difference between canon and headcanons. A vague canon lore makes her hard to work into the overall lore, while being very malleable to be worked with inside of the player's head. However, a very well developed and specific canon makes her brittle and hard to work with the player's imaginations as its much harder to not shatter her character.
[...] but I think there's already a solid foundation for a good, relatable character that I'm sure everyone including her varied fans can enjoy. Riot's writer just have to finally do something with her.
The thing is, is that Ahri and her fanbase are very...volatile. She has one of the largest player bases in the game. One poorly crafted remark, an off handed comment in poor taste, even just one wrong move can serve as a very potent catalyst. Can you imagine if they gave Ahri a relationship that implied even the slightest hint of romance? A large portion of her fanbase would implode and collapse upon itself. The backlash would be insane.
Personally I don't think there's anything to fear as I don't believe we've been given any reason to. We have to wait and see what Riot decides to do with her, if they even touch her lore any time soon. She's been sitting around in narrative stagnation for years while the champions around her evolve despite being one of the most popular characters in the game, it wouldn't surprise me if she keeps doing that even through an Ionia lore update.
I think I have a lot to fear, myself. If this lore update turns me off from Ahri, I really don't have a reason to play League. It would be a shame, as I still enjoy the game, unlike all the complaints on these boards. But again, any updates for her have the potential to be good or bad.
I apologize for the wall of text, but as you can imagine, I'm very passionate about Ahri.