This is a good point. I was thinking that you had to be a part of the contract to initiate legal actions related to the contract.
In that case I agree trying to grasp at some weird legal edge case to bootstrap a robust content pool is not making sense. It seem like such a content pool interpretation would just lead to a lot of legal confusion, without acheiving anything practically beyond artificially trying to prevent the first contributor from becoming the single point of failure.
I checked CC and GNU, and they appear to acheive what they want while not being open to any interpretation related to such weird collective pool concepts to try to anchor the availability to a larger body of people than what is "needed" for the individual licensing. As the OGL was designed based on similar ideas as these, it seem unlikely that it try to do anything drastically different and conteoversial than these.
As for the FAQ 22, that spawned this line of thinking, I still haven't grasped what they try to say with it. It might be that it is a bit clunsily formulated, and what they meant to say was that if someone published original material alongside existing OGC (hence having to be under OGL), then you are a licensee. I guess we can never know for sure.