Part of the social contract of putting a free software project up for public use and convincing Microsoft to host it for free (!) is indeed that you're going to maintain it in good faith for the people who consume it, and that if you can't you'll make a good faith effort to help the people who do.
There are good and bad ways to extract yourself from maintainership obligations. This is the bad way.
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