Absolutely nothing. They have no obligations at all, just like any supplier who provides something as-is. And I agree with the author of the post that it's wron

Absolutely nothing. They have no obligations at all, just like any supplier who provides something as-is. And I agree with the author of the post that it's wrong and unjust for people to think otherwise. But so what? That does not change the fact that a person developing FOSS supplies something—in fact in most cases they supply a ton of value.