I believe a rioter mentioned at some point in the last month or two that in every case they looked into it seems to just be a UI things where people who should be autofill protected actually are protected, even if it says autofill active. At the same time they said they didn't intentionally change how autofill works at all, so I wouldn't worry about them actually removing protection.
So if you're actually getting autofilled when you should be protected, send a bug report about it so they can look into it, but theres a reasonable chance that it's just the UI displaying the wrong thing.
edit: https://boards.na.leagueoflegends.com/en/c/gameplay-balance/nAk7zwQT-dirty-change-riot?comment=001e