Mike Johnson of PWInsider is reporting that Bryan is dealing with an injury coming out of WrestleMania. However, the nature of the injury has not been reported, and Johnson states that the situation is being "closely guarded."
As the situation is not known, there is no timetable on when Bryan may turn up on WWE programming once more.
It was just thirteen months ago that Bryan returned from what was believed to be career-ending cranial trauma, after Dr. Joseph Maroon (the physician who at one time refused to clear Bryan to wrestle again) gave Bryan the blessing to return. The decision to clear Bryan came after an extensive examination by Maroon in Pittsburgh in March 2018.
In the one year since he returned at WrestleMania 34 in New Orleans, Bryan wrestled in approximately 117 matches, averaging about ten matches a month.