From what I understand here, RedHat will terminate the contract to future code if you actually exercise your rights to the GPL code that the GPL grants you. This is effectively adding new restrictions to end users of the code which the GPL expressly prohibits.
Now, just because it isn't part of the same contract (since they haven't added some clauses to the GPL), doesn't mean it isn't part of the same distribution agreement, since it is part and parcel of the same distribution.
If the US government said "yes you have the right to free speech, but if you exercise it, then afterwards we will strip you of citizenship and deport you to Mexico" that would be considered infringement on the free speech statutes. Retaliation for invocation of the agreed upon licence terms effectively nullifies those terms, and should (IMO, IANAL) revoke RH's licence.
Breaking the GPL, and triggering the revocation of Red Hat's license to distribute various key pieces of GPL code is a massive no-go.
I've also spent my share of time talking to lawyers about various parts of GPL compliance etc. I'm pretty confident Red Hat is in the right here.
Do I like it: No.
Do I think it is stupid: Yes.