My take is that the matchup zone is always preferred conceptually. It's just that this year, we have matched those concepts with actually well-taught fundamentals from David Boyden (it was mentioned on a broadcast that he took over defense as his baby). We hedge screens better, we definitely rotate far better, we have good help side defense, we try and take away the ballhandler's stronger hand, etc. It's way, way, way better fundamentals this year.
Also, it looks like we try not to switch everything like we used to -- for example, we're not really switching Nelson onto whomever Quinn or Grace is guarding. But our perimeter guys do seem to switch fairly liberally.