I can't help but wonder if his lack of enthusiasm is rooted in getting over the shock of leaving the team that drafted him, the city he loves, etc. That's what I feel like I'm seeing. He's still processing this massive turning point in his life.
Speaking of Ayton's happiness to be here, Matisse always gives me the "I can take it or leave it being here" kind of vibes. Maybe it's just his personality? But he doesn't seem like he's really excited to be on this team.
Yeah it's tempting to separate out the Ayton trade, but it's intertwined as part of this. It's possible they could've made the Ayton deal separately, but who replaces Grayson Allen? The article touches on quite a bit, including Phoenix/Ayton.