I'd have to say No. He the added weight probably added to his pop. But i would have to say he lost more in punch dynamics and technique through his inactivity than he gained from the extra weight.

In his early days much of the power tyson generated came from a combination of using his legs to coil and get his body moving forward, Him turning at the waist, and him snapping off those heavy shots at the elbow. All of those factors with as someone already stated above, his speed... made him a monstrous puncher... especially when it came to ripping those stubby hooks.

Post prison tyson had noone to put and keep him on track so he took short cuts. He didnt use his legs because it wore him down faster... he didn't turn at the waist like or as much as he used to.. Instead he pumped his hands and and shoulders instead of moving his head... and he didn't snap his punches and instead went for those looping shots.... miss... and then wind up in his opponents chest a lot of the times because he tipped forward. His balance suffered too.
He still knocked a few people out when he started using more straight shots than he used to.