Comment by toast0

> I'd estimate figuring out who has which rights would take at least a year and a couple hundred grand in legal costs to get each potential stakeholder's attorneys to locate, review and analyze the documents and issue a binding legal opinion.

If you just went ahead and did the release, the stakeholders might well do the research on their own dime. Of course, those that do have rights might not be interested in negotiating a license at that point. And, there's a chance of getting access to a development archive if you're doing an authorized release.