first of all, I don't know where you heard that about Dolly, or when, but I am sure it is not accurate.
regarding the legality, no one is going to play with that money. The issue is that the earnings on it, which belong to the shuberts, are going to be millions of dollars (over and above the usual millions from the "normal" advance) and I suspect there will be a deal that gets some of that to Rudin one way or another, though I think in this case it's going to be an equity stake. Note also that Jackman has a longstanding relationships with the Shuberts going back to Mr. Schoenfeld, and it would not surprise me in the least that they were involved in packaging this. As usual, in the words of Sergeant Schultz, I know nothing.