Oh this Matsudo-sensei we all know all right, alternative timeline didn't change him a bit. So this IS AU and pastime club most likely isn't a thing here, I wonder why author decided to go this way.
Tbh I got the impression that they got bored of, or got sick of writing for the asobi trio.
After the whole Kasumi/Aozora drama not only did Kasumi disappear but the other two were used to flesh out and develop the 3rd Year girls until pretty much the final third of the series was all about them with some trio peppered in until the last two chapters of the series when the trio had to show up cause it was ending since it was originally about them.
I'm pretty sure (at least while I was reading it) that the trio's dynamics got written into a corner that they didnt or couldnt figure a way out of and just switched to the older girls, or just lost interest.
Which is kind of a bummer cause the lore in asobi asobase was unhinged as hell, which might be another reason why it went AU with this one. Vampires and zombies and being cursed to say vegetable juice when you try to spill a secret is hilarious but once it started focusing on the 3rd years it went back to being grounded enough to be slice of life yuri again lol
The comedy and facial expressions were absolutely bonkers though and I miss that.
Not too big a deal, but the characters feel like they're 3DCG character models being posed in some panels (even more noticeable in the first chapter's color spread), which from what I remember hearing might have to do with her having mangaka issues like back and wrist pains and why the series is on the hiatus boat