Some old scouting reports describe him as "two way" and as a "buzzsaw." A lot of recent reports bash him for being too outgoing, having personality, and too flashy on offense.
If it's a personality issue and they can get a discount, great. If he really plays buzzsaw hockey, fine. It seems his advanced stats are good this year, he's just playing on a crappy team with bad goaltending.
I'm not sure he's exactly what the habs need, so it really depends on what the price is. The ducks need D prospects so there could be a fit. The cap would be close, ideally they would send at least one salary at least double or triple the minimum the other way. I guess Mailloux for Zegras with some adds might balance out, but I'd expect a bunch of misgivings on both sides. The bidding war could easily get out of hand if one of the other teams really likes Zegras or really doesn't know their own prospects.