I’d bet they just added it to their global .gitignore where it should be, then removed it because they didn’t want their private dot files committed to a public repo.
I don’t think this user knows much about git works. I don’t think this is nefarious or “vibe coding” as it’s colloquially known to be. It’s a bit much to describe all LLM use blindly as vibe coding, when vibe coding usually means just blanket accepting AI content.