Yeah it's definitely going to be Huston. I think career-wise, both Michkov and Celebrini have tremendous ceilings (so does Hutson), and so it's not as obvious to predict who ends up the better player in this group - but for rookie season it'll definitely be Hutson.
He really turned it on in December, and helped turn the Habs season around. Habs were in last place to start December, and when Hutson got going they slowly rose up the rankings.
And then - at 4 Nations break, Habs were on a losing skid and tied for 2nd to last in East...and since then, Huston is #1 in the NHL with a +18, and just overall extremely valuable to Montral's performances and wins.