[yorwba]

You could have a company-provided Anki account for each user where you add and remove cards just for that user. (I thought you might even be able to use your own server, but that doesn't seem to be an option for the iOS app: https://ankicommunity.github.io/Tutorials/anki_custom_sync_s... )

Then placing a "this has changed" notification card at the front of the new queue only for people who learned the old information is as simple as checking the corresponding card's review status in the database.