These crit item changes are going to make cait and vayne more of a problem than they were
A large majority of players were asking for caitlyn nerfs for at least 2 months when Riot decided to just buff the other ADCs. That didn't fix the problem of course. And as someone with a level 7 vayne, she was able to one/two shot people before the q buff and all they did was revert it.
These changes can't go through without any nerfs to them. It would cause more problems than it would solve.