The mw-undo, mw-reverted, mw-new-redirect, mw-changed-redirect-target, mw-manual-revert, and mw-rollback tags are no longer activated by default, and are listed in Special:Tags as "No longer in use".
Steps to reproduce:
See Special:RecentChanges, filtered by tag
What actually happens:
All tags stop being applied at around 18:18 UTC
What should happen:
Tags should still be applied
It looks to me like T266067 might be related given the time when it was merged, but I'm not sure.