No, there is no social contract here. Microsoft gives free hosting because it's cheap and also provides a path to their paid offerings. People share stuff they work on for fun, to help flesh out their resume, to get help, etc. There's no reason for a maintainer not to drop a project in a heartbeat if it becomes the slightest bit of a burden.

There are no maintainership obligations unless someone pays you for them.

No it's not.

Also read the link. This is apache 2 licensed. Even in whatever imaginary world where there is such a social contract, there is thankfully a legal contract that includes disclaimer of warranty.

Sorry but this is an outrageous perspective, at no point does git init / git push am I committing myself to a social contract, in fact there’s probably a license that states no warranty and no support is to be expected… maintainership obligations gtfo if you’re not here paying for support