If they wanted to have it on Tuesdays, they would've just put it on Tuesdays in the first place. Tuesday vs. NXT is vastly preferable to Saturday vs. fucking everything under the sun.
The reason they went for Saturday is that WBD has basketball on Tuesdays and Thursdays. Having said that, it sounds like NBC is in the mix for the NBA and who knows if WBD will want to spend the 7-8 billy that the NBA wants.