I'm not misunderstanding anything. CVE involves a third party and it's not just a number. It's a number and an evaluation of severity.

Things which are usually managed inside a project now have a visibility outside of it. You might justify it as you want like the need to have an identifier. It doesn't fundamentally change how that impacts the dynamic.

Also, the discussion is not about a specific bug. It's a general discussion regarding how Google handles disclosure in the general case.