I don't understand...is it really costing them so much in bandwidth or server space? Are they planning a full-blown, paid sequel??
I really don't think it has to do with logistics at all.
It's probably just an experimental game they published, just to make sure employees can work remotely from home without any issues, and then plan to delist the game after everything has settled in place to continue working on actual titles in production.
After all, this game's budget is 0 dollars, since it's written in the spare time while the Nintendo developers are setting up for remote work and they just wanted to do some exercising at home, and came up with this game idea, pitched it in, and got approved.