The question at what point submissions can be revoked is a general one, not tied to CLAs, and it's come up in the past (eg. in Samba). The musing about whether the FSF owns copyright on stuff you haven't submitted seems both unimportant and an invitation to armchair lawyery.
Now, I don't like CLAs either, but this didn't really add any useful data. It read more like FSF-baiting :(