#2 – WWE wants him to 'earn' it again
WWE creative might just squeeze in one more Seth Rollins vs Brock Lesnar match before moving on from the feud. They did give him the Money in the Bank contract out of nowhere earlier this year, so it won't be a surprise if he wins the King of the Ring tournament too.
The other plan for Lesnar would be for him to continue beating up Rollins week in and week out before the management agrees to hand him one more opportunity. He's certainly not going to go the Christian way and chant 'one more match' every time he is on TV; Brock will just do what he's best at.
While this is a possibility right now, we really hope WWE doesn't go down this path as the fans are clearly not in favour of it and will never be.