The contributions I’ve seen from such people in the open source projects I’ve worked on ranged from zero to negative value, and involved unusually large amounts of drama.
I can imagine things are different for some projects. Like maybe debian is trying to upstream a fix?
Even then, can’t they start the PR with a verifiable intro like “I maintain this package for debian.”?
For the other 99% of welcome contributions, intros typically are of the form: “I was hired to work on this by one of the industrial teams that maintain it”