I think the problem is Mei doesn't really have any redeeming qualities or hidden depths, unlike even the biggest assholes in this series (Jashin-chan included). And is unlikely to have any, barring some rethinking of her whole character.It's kind of telling Yukiwo doesn't know what to do with Mei, even though it's kind of obvious.
Ecute -> collection -> Atre-shaped consequences. Bish bash bosh, Mei still relevant.
Either Yukiwo either somehow forgot that subplot/character tendency or he doesn't like it anymore.