I'd go higher than that.
Carson just turned 18yo four days ago. He's one of the most NHL-ready of any of the D prospects in this year's draft, but he's still so young. Not many 18yo dmen in the NHL right now outside of Schaefer. Calgary is going to want to see how he does with moving up a level and how he handles it. Look at how dominant Verhoeff was in the Dub and the adjustment needed last year when he moved up to the NCAA. Calgary has shown to be patient with NCAA prospects (Reschny comes to mind).
I'm betting we see him line up on campus this fall in the Green N White.