If you wanted to somehow make coordinated disclosure into a legal framework, that would be an interesting and complex project.

But it’s not the law anywhere I’m aware of today, and I’d not support it becoming a law.

This is kind of a thing already in the EU. Under NIS 2, vulnerabilities should be notified to a CSIRT as well as upstream, and the CSIRT shall identify downstream vendors and negotiate a disclosure timeline. I don't know whether they're any good at it or not, though.