I can say fore sure that there were verified fake Elon Musks before the rollout.

For example

https://twitter.com/iamsimonyoung?s=21&t=bk20O5m6wZsdz0lQ9AT...

was posting as Elon Musk at least until 20221102. There was at least one other Elon Musk that was regularly spilled into my timeline, sometimes right before or after the real Elon. These accounts had also the same profile picture. It took me a while to realize that some of these posts are satire. Pretty much the scenario the blue checkmark was supposed to prevent.