You cannot actually believe something like that. Absent injuries, Kaprizov is a 100 pt per season player and a dominant force on the ice. Demidov has no chance of being one of the best players in the league, and illusions produced by the lacking quality of competition in the modern KHL do nothing to dispel reality.
Yes. Fan expectations are... rating of the prospect?
You literally just repeated what I said. He is vastly overrated by many fans of the Canadiens who believe that he's going to become "better than Kaprizov" or the like.
Best D+1 in a league that's vastly worse in terms of overall quality of competition than it was when the previous record-holders achieved their success. It's stated in my post.