[metaphysician]

And they weren't negotiating for the FF as a whole, just shared usage rights for certain FF supporting characters.

IMO, Marvel probably *does* want everything back. However, being seen as wanting them back would be counterproductive, as then everyone currently holding rights would be encouraged to hold them with a death grip in order to demand considerable payment. So, stay cool, focus on their own thing, maybe offer little deals here and there, but largely wait for someone *else* to come to the table.