There are two issues here.
Firstly, one can produce an argument for misbehaviour obtaining any badge. It is a feature of having badges and isn't really a major problem. Once people have the badge, they tend to stop.
The more important issue is rolling back edits in order to keep unpleasantness on the site. I've seen this done on a few sites across SE. It ...
As Raffzahn said, this is a retroactive awarding of the badge due to the change that made upvotes on questions worth +10 reputation. If you take a look at the 2018-11-19 entry on your reputation log, you'll see that it's correct.
Not all badges do appear in achievements. Users with more than 200 reputation don't see certain bronze badges in their inbox.
There is a question on the main meta to list those bronze badges that do appear.
Which badges do not cause a notification for experienced users?
Gold and Silver badges always appear.