Originally Posted by zz9
A specific actual proven example is not "theorizing about it". It clearly happened after the WGA agreement you mentioned.
It showed they could agree to such a concession when they thought it benefited them. As you say they will be far less willing today, but if JR Rowling offered them a new idea but wanted concessions from their standard contract, they'd listen and they'd deal.
Any clause in any contract can be negotiated. You just need to give them a good reason to do so. Same with profit participation. We all know those profits will never materialize but people like Schartzenegger at his peak could get them to agree to a cut of the box office. They agreed to change their standard contract, and in a big way, because they thought it was worth it.
Again, a difference between "could that happen" and "would that happen." Hypothetically, a writer could sell a script to a studio for 51% of their stock. Would that happen? No.
Would a situation analogous to the George Lucas/STAR WARS deal occur again? I doubt that has happened often, if at all, with original properties since the ramifications of that deal became apparent (remember, STAR WARS contributed in many ways to changing the movie industry as we know it). But again, if you can find recent examples, please provide them.