I can’t believe how many people fundamentally misunderstand the spirit behind the GPL.
It helps to consider “the software” as a single snapshot in time, with the GPL’s intention that the consumer may make their own fixes, rebuild, and redistribute. Check.
Remember: “Free as in freedom, not free as in beer.” Selling open source software has always been explicitly allowed, as long as you make the source available to those who receive it. Check.
What the GPL does NOT provide is guaranteed access to maintenance and future versions of said software. Again, it applies to a snapshot, as delivered.
In a nutshell, the customer receives open source everything they FOR A PARTICULAR VERSION.
I see no problem — either in spirit or letter — in Redhat’s approach here.