> Some of the banks profits now went into paying developers for the changes in the fork. Do you think the bank's executives will just want the money they put into the fork to potentially benefit all of their competitors by having them make a pull request to the original software?

Given that that is how they can avoid having to maintain a fork indefinitely, and that that is the fair thing to do after you profited from the gift of others who did the same: Erm, yes, they absolutely should want that, and most likely it is in their own best interest.