Tyson with his speed, explosivity and aggression would present a wholly different type of threat than the one Foreman did, which was more in the manner of raw power and the psychological pressure of his come-forward durability. Where Morrison was able to avoid the brunt of Foreman's stuff by backpedalling and running around the ring he wouldn't be able to do that against Tyson, who'd catch him with something big and unexpected and follow up with fight ending shots before Tommy could recuperate. Sure Tommy was game, and I don't think it'd be a total massacre; I think he has his moments early, and possible stuns Tyson, but I don't see much chance of an upset here.
Pretty much as I see it. Morrison was a bit like Cotto in that although he could box on the backfoot for stretches at a time, he was clearly uncomfortable doing so and it seemed to take a physical and psychological toll on him. Against Tyson I see Morrison burning up a lot of nervous energy just trying to keep Tyson off him. I think this does him in before Tyson's punches confirm the job.
Tyson was wild and his technique was very poor but I think he could handle Morrison who threw little more than a lefthook. I think Tyson takes him out within three rounds. Morrison liked to punch up towards the bigger guys so I think he would have had a hard time landing that hook on Tyson who had similar problems with the short Buster Mathis but would be able to find Morrison's chin fairly easily.
But Morrison was about as far ahead of Botha as Tyson '95 was ahead of Tyson '99. Botha relied on his reflexes and awkwardness for defence, while Morrison could have good head movement and footwork, at least for the first 4 rounds. Look at Morrison against Mercer in the first four rounds. That's some very skilled boxing against a prime Mercer. When he was afraid- as he would be against Tyson- Morrison could box very well. Just not well enough to stay away from Tyson all night long, which is what he'd need to do in order to even go the distance.
Morrison also had a good right uppercut that could land against Tyson. He could also jab if he needed to, though he didn't do it very often because jabbing from the crouch exposes a square-on boxer like Morrison to the right hand. Morrison could throw flashy combinations and work the body. Morrison's problem in this fight is not his offence, but his defence and durability.