Anaheim has made it clear that it is selling everything not nailed down to rebuild hard. Why do that and then trade a top prospect for a veteran? It doesn't matter how much the OP likes McTavish. This isn't well thought out, or more likely, is just a flighty post in the first place.
Anaheim says no, and it's less a commentary on the player (Chychrun) than on his age, contract, and Anaheim's emerging overall approach. Given their moves, the Ducks won't be contending within the three years left on Chychrun's contract. He's most attractive to a team at the crest of its competitive wave, not the trough.