I understand that "just update tags when someone changes a post" is an efficient way of keeping up to date with aliases and implications, but it does have a funny side effect.
I just did a few changes, then looked at my edit history, and saw changes that I did not intend to make.
I've got to say, it spooked me a little bit, thinking I accidentally deleted something :P

If you see tag edits that you did not add/remove, it is likely just queued alias/implication requests making its rounds.
You don't have to worry about it as the tag changes are intentional.