Sabre Jr. turned them down due not wanting to go through NXT, Ospreay would have been severely restricted if he signed, so that's probably why he turned them down.
Heck, Hangman Page turned them down recently. Wrestlers on the indies love the freedom to do whatever they want, and use whatever moves they want.
If anyone like Kenny or the Bucks did go to WWE, they would get most of their moves taken away due to WWE questionable rules.
No doubt, and they dont allow people to have the same moves usally its so dumb