You are crazy if you think the footage they would get from TNA (incomplete or not) is worthless. Guys like Hogan, Sting, Flair, all spending considerate amounts of time there that can be added to any features WWE does on them. Even current personalities like Booker T have a decent chunk there. And think about the active roster. The big dogs of NXT like Samoa Joe, Bobby Roode, even Aries, who are all but guaranteed to be upto WWE at some point and become bigger names. The endless "Downfall of TNA" features they can do. And let's not forget the crown jewel, the biggest chunk of AJ Styles career. Even people who might get signed by WWE later on. EC3 is obviously a guy they would love to have back. All the "journey" footage counts for something.