You can argue about whether the "publicly announced existed" part since they don't advertise for any single package, but that's the ecosystem you buy into.
The way you've written this is substantially misleading. RedHat receives notice of the vulnerabilities so they can prepare packages to be available the moment the embargo lifts, which I guess technically could hit the public packages a tiny bit earlier, but they are not releasing fixes of embargoed vulnerabilities to their commercial clients before the embargo lifts.
This is substantially different from the policy I've quoted that I am objecting to.