I suspect you're reading some specific technical meaning into the word "block" that the PR and release note didn't intend by their informal use of the word. But I'm unclear on what technical meaning you have in mind.

Before the change, gc "just gave up" after seeing a resurrection, ending the then-current cyclic gc run. It that sense, yes, resurrection "blocked" gc from making progress. It did not, e.g., "block" the interpreter in the sense of deadlock, or of waiting for some lock to be released, or of waiting for a network request to respond, or ...