I don't think there's anything particularly "wrong" with Zegras in terms of some nefarious hidden locker room cancer or whatever, he's just not THAT good. The talent is there but as an NHLer his overall game is just not that special, he's a useful top 6 forward right now but not currently on track to be a true franchise/core guy. The Ducks are cagey about paying him as a key player and they think they're better off with their 2 big horses down the middle in Carlsson and McTavish. Zegras is going to want to get paid like a C and the Ducks don't think he's going to be a C for them, and they might be concerned that he's already fairly close to his ceiling rather than seeing the 61/65pt seasons being signs of a future 90+ point dynamic offensive talent. It makes a lot of sense for them to want to trade him based on who he is on the ice, particularly if they see him as a winger and just traded for Gauthier who probably plays on the wing as well. He's a player that likely has more trade value than on-ice value for the Ducks in the eyes of their FO, I don't think there's anything more to it than that.
I'm not a huge Zegras fan, but I'm not against trading for him in principle as there's a pretty natural fit on the wing with Dach, and he'd be a great addition to our PP in the short and long term. My issue with it is it just that I don't see a fit. We're not trading Guhle, Hutson, or Reinbacher for him, and they're not taking a package of Xhekaj/Harris/Barron and magic beans for him. We don't currently have a piece to trade that's valuable enough to the Ducks but expendable to us.