I will take a stab at this... I am guessing it will be a brief model. I don't see this bike being super successful in the States, as Americans have a love for large, high cc bikes.
I own a CBR250. For what it is, it is a nice bike. But Americans view it as a beginner bike that you ride for a while and then get a bigger bike. This is not a fair characterization, as I am not a beginner, and I have owned much larger and faster bikes.
I am thinking the Grom will have limited appeal. This bike will attract the people who used to own a bike with an engine like the Grom has (Honda Cub, Trail90, etc), kids who want a cheap stunt bike, and people who want cheap transportation.
For all the Grom fans... this is not a slam on the Grom from me. The culture in N. America is what it is.