I'd say Cohen is entirely Canadian. He has this very self-deprecating humor that you don't really get from Americans.
Leonard's first album had amazing production by american producer John Simon (who also worked with The Band, Simon & Garfunkel, Janis Joplin), probably the best in Cohen's entire career, so he chose well deciding to work out of Columbia's studio in NYC...
Not sure what else you can call someone from USA, so I guess it makes a bit of sense.
I would not be surprised that one of the lesser reasons Dylan was awarded this year was to open the door to others including Cohen in future years.
Not to mention that Dylan's awarding might have the more subtle effect of encouraging contemporary musicians, if they are not already doing so, to commit to more enduring songwriting than otherwise just making a weekly Top 40.