Wouldn't live NXT be much more attractive to Fox? The cost of the live taping would be more but they would be getting 400 million a year. Triple H said it could go live someday but it would be hard for him physically to do RAW/Smackdown tapings and then be down in Florida by Wednesday for NXT. Given that it's 2018 and technology being what it is, can't they have him run the show from a remote location?
This also would open up the door for 205 Live to slide into Full Sail/Atlanta Center Stage after NXT at 9PM. The crowd is just dead for 205 Live in big arenas. And they can't tape it before Smackdown because if they're in a west coast arena it would start live at 4PM. I would think that would make it tough for people to get to the arena that early.