It doesn't really matter if they've contributed or not. They still need to abide by the terms of the license.

In what way is Red Hat not abiding by the license? My understanding is that Red Hat is making the source code available to their users via their customer portal. I don't think that they have an obligation to make their source code available to non-users.

They have an obligation under the GPL to allow end users to redistribute. Terminating the subscriber agreement for redistribution is punishing the user for exercising his right granted to him by the GPL.

I had missed this point earlier. Thanks for clarifying. This does indeed look like RH has put themselves into a quagmire.

End users are allowed to redistribute the source they received from Red Hat at their hearts content. What Red Hat is terminating, from my understanding, is the future access to new binaries and sources due to the service contract becoming void.

Your server will keep running, you'll have the sources for all the server's binaries, but no more support.