No, I agree, and understand that point of view; we even get that from Allison with regards to Perry, but not really the rest of the group. Besides it's a two way street, most of the rest of the group never even acknowledge Allison either. It's just weird to me to have Allison show up at all, to the few gatherings she has, and there is no back and forth between her and another onscreen character besides Ian. Even if you've grown apart, you can still have polite chit chat. Perhaps that's how Allison comes back into the group, that she is mature and moved past the petty dramas of high school.
Allison and Cindy could honestly find a bond in that regard as both of them are feeling the same thing, that they're... not necessarily better than the group, but that they have bigger dreams and aspirations than those of Perry, Wade, and, though I would disagree, Emma.
But part of her character arc can be developed by her reintegration into the group. Realizing how much Wade is struggling with depression, that Perry is finally growing up and taking responsibility by working at the cafe, that Emma is doing a whole host of things: from restoring and organizing the community center (Stardew Valley reference?), continuing to play music when the others stopped, organizing protests, and working at the record store. Or it can prove her point if Ian sabotages Wade, doesn't encourage Perry, and Emma listens to Lena and connects with Seymour.
Leaving Allison out of the group dynamic, the way EK has, is a wasted opportunity. Though I get trying to account for all those additional variables would be obscene work when EK already has enough on their plate. It just feels like Allison could have been a coworker to Ian or someone else outside of the group of friends and it wouldn't change the story at all. Whereas having her be a part of the friend group in the past, but then never interacting with them in any capacity is just weird.