Ubuntu Pro is a subscription offering for Ubuntu users who want to pay for the assurance of getting quick and high-quality security updates for Ubuntu. I tested it out to see how it works in practice, and to evaluate how well it works as a commercial open source service model for Linux.\n
None of this affects what happened “back in the day” which is what I was talking about.
That said, my understanding of the current packaging philosophy of RHEL/CentOS Stream is that embargoed security fixes go in to RHEL first, then to CentOS Stream once the embargo is lifted (that’s pretty much as you’d expect), otherwise everything goes in to CentOS Stream first. Unless you have counter-examples I’ve not heard of?