I have an idea why they do this with the supermario remaster. They are making it a limited time release because probably at that that moment they will announce their new switch console. And they will re-release it only to the new console, making everyone that didn't buy the remake on the old switch, want the new switch to play the supermario remaster. This is just an idea to explain the limited time release, otherwise i find it such a stupid decission, because this remaster will sell like hot baked bread for many years to come :/