He was intimidating because getting hit by him hurt; a lot. So while I think people will approach him with more confidence, it doesn't mean his punches will hurt less. Also, nobody likes it to the body, by your logic, everybody is a bitch. Fine with me, but accept that being punched hard in the stomach is not uniquely his own personal kryptonite. Jack is pretty linear with his feet, and if he covers up high as much as he usually does, Kovalev can straight punch him to the body (some Kovalev is actually pretty good at). Kovalev gets seen as a linear killer, but he fights with his hands down and doesn't get hit a lot. Why? Because his defensive footwork lets him cover a lot of ground. He pops back and then he pops back in. Not a lot of people talk about it, but that's part of the reason he can fence at range and not get hurt a lot. Although the Ward rematch indicated a lack of that, that was a failure on his part and credit to Ward.
The one thing I agree with is Kovalev's state of mind. If he gets a trainer, cooperates with them, and is in the patient, confident head space he used to be in, I don't see how Jack will win.
By the way, Jack only looks like a good body puncher when his opponent's feet let him be a good body puncher. Ward was fluid enough to get inside and confuse and also strong enough to work inside. Jack is not as physically strong as Ward. Ward's physical strength is deceptive. Jack does not have that kind of footwork, or the dynamic movement. Jack is a good fighter, well-rounded and steady, but it would take a obvious decline in Kovalev's mentality for him to lose to Jack. That part I see.