I just encountered that the Figma detached text styles bug has affected another of our projects.
The batch “reset text style” command was no longer usable as a workaround to fix the issue.
I was about to do a test by creating a new component in the UI Kit (the library file) with one variant set with a library text style and the other with the style removed - then testing the instance in another Figma file where the library is used. What I encountered when I attempted to publish the library was that for some reason it looked as if all the text styles were previously removed and are now added back….
So, I published the library and everything was back to normal in the Figma file where instances of the components were used (without having to accept any library updates).
Maybe the issue is not in the instances but in the library file, where for some reason these get unintentionally removed from the published library without notice?