The phrase responsible disclosure doesn’t have a precise definition. Instead, it can only be understood in terms of its opposite, irresponsible disclosure, which is defined as “any disclosure I don’t like”.
Instead of using a phrase that encodes a value judgment in place of a description, let’s pick a technical term that describes what’s happening: selective disclosure. This phrase is then neatly contrasted with its opposite, full disclosure.
Some people like the term coordinated disclosure, although in practice it often isn’t.
Also: regarding embargoes.