With Yoshida I reckon that it's probably just a lot harder to fit her into the group dynamic. She was largely there both for physical abuse and to protect Tomoko but Tomoko doesn't really need the latter anymore and is now largely in situations where she comes off as more grounded so less opportunity for "Tomoko does something sexual, gets hit" jokes. When we get the "Tomoko eats lunch with Yoshida, Anna and Rena" chapter I'm sure there'll be plenty of it though and I'm guessing chapters involving the delinquents will be used to break things up a bit.
Mako's never really been much of a character even prior to the post-Disneyland chapters. She was largely just Yuri's friend who's really nice which is the same role she has now. Again though if we ever get Fang focus I'm guessing that we'll see stuff involving Mako too.
Plus it could all just be a matter of Nico liking the way this core group of characters interacts. You've largely got five characters which is quite a bit and all have wildly varying personalities: observant and socially awkward Tomoko, outgoing and high strung Nemo, quiet introvert Yuri, popular sweetheart Katou and out of her element normie Akane. All of them balance each other pretty well between wacky comedy stories and down to earth stories and in situations like that it can be harder to find places to work in more one note characters like Mako, Yoshida, Komiyama and such. Things evolving and settling into place regardless of what ideas you might have had at the start are just the natural result of writing.>>179539431>Nemo>yandere
She's just competitive and kind of looks up to Tomoko. If she really was crazy she wouldn't have had the perception or sense to tell Tomoko to go talk to Yuri when it was clear she was upset with/because of Tomoko.