I get the analogy I just think it's overblown when it comes to rink width. It's a fun topic to bring up but there isn't any evidence, at least among skaters, that there is some years-long adjustment process or even a games-long adjustment process.
There are KHL teams with 30m width, 28m width, and 26m width. They all play each other, it's the same game. There are international tourneys where NA kids go and win on 30m ice, and there are also international tourneys where Euro kids go and win on 26m ice.
It's not going backwards with Bemmer because he never mastered Europe to begin with. It's not like he's a great Euro player that just need to learn the NA game. He needs to become better at hockey. Guys that have mastered Europe don't take years to figure out the NA game, they're at their level right away.