Neither game has a release date, although we did enjoy the recent beta test for Splatoon 2. It’s likely the Nintendo Direct will give us much more concrete information about both games, hopefully information on when we can expect them to be released.
It is likely the question of whether these are kids, or if they are more closely related to the squids of our world, will not be answered so that Nintendo can continue to stretch out the suspense into future games.
Arms, on the other hand, is a fighting game that can be played with either motion controls or by using the Switch’s buttons and analog sticks. You can check out some video of the game in action if you’re curious before the Nintendo Direct begins; the game has already inspired a strong following online.