Also found this, which kind of supports what I posted about the disagreement with higher ups:
Sudden Departure of Two V.J.'s Disappoints BET Viewers
Mr. Calloway suggested that difficult contract negotiations were behind his decision. "It came to a point where there was an unsatisfactory offer," he said, "and it was time to move on and do other things." The relationship between the V.J.'s and upper management had been strained in recent months, Mr. Calloway said, adding that, "there's a new power structure at the network and it seems like they're moving in another direction."
Sudden Departure of Two V.J.'s Disappoints BET Viewers