There's not enough torque or horses to put too much strain on the transmission. You will want something bigger before you catch any slipping. You could very easily get 50,000 miles on this bike. It's all about maintenance. I would rather have a well maintained high mileage bike than a low mileage poorly maintained bike. I have seen a Ninja 250 in shop getting a motor replacement at 30,000 miles (the owner did not have any mechanical knowledge for maintenance) and i have also seen the same model not needing a motor replacement until almost 90,000 miles.
Longivity of any motorcycle is up to how much you take care of it.