Maybe add some speed next Olympics. They look completely outmatched with more space on the big ice.
I was thinking the same thing initially, but I've been truing to analyze the rushes from both teams, I it looks like the US team plays a more hermetic, 'wait-for-them' defence, while the Canadians leave more room for the US skaters to come in. They play too deep in their zone.
Look at that last shift. See how much space the US D had at the Canadian blue line? The Canadian 'box' is way too tight, and too close to the goalie.