You're assuming because Mrtka could hold his own in Rochester theoretically, that it means he's not being challenged in Seattle. I disagree. He can learn and develop his offense more, while also leading a team. Ultimately, this is pointless because Buffalo will do whatever but I don't think 43 whl games means he's somehow mastered the lower level because he looked fine to good in a few preseason games.
Rochester has like 11 defenders on their roster. It can wait a year.