Things are back to normal. I guess the game don't really like collab events

The new girls are okay but I'll pass. You mostly have to use them with other collab girls I guess (okay they could shine individually but why using one of them when you can use another top tier girl?). Event girl abilities for Slash girls with no family is nice for many old collab girls like Akane or Marina (too bad I missed dear Marina).
There is some fun stuff to do with them if you're an old whale with all the previous collab girls and enough money to get all of them now.