Zach Lowe on the Lowe Post podcast said "I think Ayton to Nurkic is downgrade [for Phoenix]. I don't even think that's arguable. I think Nurkic has lost a couple of steps in the last couple seasons defensively, he is not quite as mobile as Ayton and not as good of a jump shooter as Ayton". He goes on to say he watched ALL of Deandre Ayton's pick and roll defensive possessions from this past postseason and that Ayton was "a lot better than I remember".
So Zach Lowe is certainly on board with this being a big upgrade for the Blazers