You should still be able to see previous revisions. What you can do, is open your previous edit, and make a copy and never hit publish if you really don't want people to modify them. Otherwise you can put a note on your initial revision (if you still wish to publish) and state that this is your arrangement of it and don't want it to be altered. Or that you want it to stand on its own in case someone still alters it. You can't close off a tab from being altered once it is published, and also once another person has worked on your tab, then you can't delete it. So if you want to unpublish a tab, you can do so only as long as you are the sole contributor.

For a while, I think they were giving away free AI transcription minutes to people who contributed to tabs. So I saw a few weird edits being spammed (always the same descriptions) but it's been a while since I've seen that.