Keith Lee made a huge impact in NXT, and was expected to be pushed as a big star on the main roster. Unfortunately, his move to RAW last summer delivered a series of disappointments, and for reasons which still aren't entirely clear, his ring attire received a goofy overhaul (as did his previously awesome, and now thoroughly generic, entrance music).
It felt like Vince McMahon was trying to recreate Lee in his image, but the former NXT Champion has been M.I.A. since February. He was supposed to win the United States Championship that month at Elimination Chamber but is thought to be dealing with an unspecified injury.
On May 11, Lee indicated that it was an important day for his future, though nothing has been said since (it only served to further fuel more speculation among wrestling fans).
Now, Lee has responded to someone on Twitter who asked what's next for him and it doesn't sound good. If Lee has suffered a serious concussion, it could be that he's simply unable to get cleared by WWE's doctors, similar to what happened to Samoa Joe before he was added to RAW's commentary team.
Hopefully, we'll get a concrete update soon because it's a real waste to see him left on the shelf like this.