I can see how this would have helped in this case.
As I see it, the distributions are mostly relying on the upstream provisioning of the openJDK project. So if they fix this issue, it shouldn't take long until we see updated packages in all major distributions. This might be a problem specific to the openJDK build process, so a different package source would help in that case.
But as mentioned above, Azul usually doesn't provide out-of-cycle critical fixes without a paid plan. And most people will still use whatever the distribution provides - so this is still an issue regardless of alternative package sources.
And since I assume that many or most running JDK instances actually are coming from the distributions repository rather than an alternative source, and there is literally no outcry regarding the missing packages whatsoever - I fear that there are a lot of vulnerable software systems of people not knowing about it right now.