Does Github have a feature to just switch all my private repositories to public when I die?
There could be any secrets (API keys, etc) in a GitHub repo.
(And it should have very clear warnings before you turn it on so you don't accidentally make things public that shouldn't be. Plus, there should probably be some sort of way to tag which repose would still need to stay private even after your death.)
Coma, incarceration, etc.
But it puts the onus on the user to decide what they want to happen in those circumstances rather than leaving on Telegram to decide whether such and such person is living or dead.