In my experience, "silently overwrite" appeared regularly in technical writing long before LLMs were a thing, because it's a useful concept to be able to point at. "Silently go unnoticed" is kind of redundant, though.

Accidental things and silent things are very different. Accidental means you didn't mean to do it, silent means you don't know you've done it (or might not if you want to get picky, you could notice).