Soundwave on 01 May 2017
I'd be fine to be honest with 2DS/3DS being kept around for another 2-3 years even, so long as the focus is clear that this is a product for entry level kids and cheapskate parents.
This lets kids get hooked on the Nintendo IP and as they get older, they can graduate to Switch, which should maintain it's current marketing scheme at a older audience which is working great.
