Eh, laws aren't quite that clear cut. Remember, Wolverine first debuted in the Hulk, but is unavailable for the Marvel films because he's an X-men, and those rights were sold to Sony. On the other hand, Scarlet Witch and Quicksilver were available for the Avengers as long as they weren't referred to as mutants (admittedly, everything surrounding Marvel movie rights is a mess and makes little to no sense at the best of times)
Really, it's a roundabout way of saying that without looking at the actual deal, it's impossible to tell unless they clarify. I don't find it likely that they'll clarify until they need to - it adds a bit more mystery, considering literally all we know about the world so far is in the fiction and on the cards so far (beta RPG is a good indication for some things, but subject top change, so it isn't concrete yet)