No - he peaks around age 30 like most Heavyweights. I think at 27 he is just entering his prime in the next few years. Expect great things....
AJ and Whyte both were ref assisted defeats and he STILL almost had Whyte out, and AJ couldn't even British stop him. I think that Whyte loss based entirely off dirty tactics changed him and the change in mindset may make him a fair bit more of a threat, so long as he doesn't get points/DQ against him where others wouldn't have.
I hope you're right. I really like Parker as a person and as a fighter, but I'm just saying things as I see them. I haven't seen any improvement in Parker either physically or skills-wise for a couple of years now, so it's hard for me to see him suddenly break through at the top like I thought he might back around the Takam fight. He's plateaued IMO.