Wrestlemania is coming up and everybody wants in for a piece of the pie which means guys who have carrying the company this whole time have to take a step back just to get some of the crust. Something Punk practically cried foul about almost two years ago.
Unfortunately, in Bryan's case, WWE gave him a chance at redemption and all his supporters weren't there. He didn't draw the numbers they wanted for SummerSlam (because almost everybody was illegal streaming it I bet) and Vince lost faith in him. Not Bryan's fault, but shame on his fanbase for not coming through for him on ordering when he needed it the most.
So when you got proven draws like Lesnar and Batista coming back. In a way, I can't blame WWE for playing it safe. Best for business unfortunately.