I'm fine with it as long as the games are not really significant/resource intensive (3DS already has a large enough library).
What does a 5/6/7 year old really need a portable HD console for? 3DS has hundreds of games and virtually every Nintendo IP that are perfectly fun to play and introduce them to those characters for 1/3 the price.
I think it's fine if 3DS is basically the "kids" or "entry level" Nintendo machine for kids that want more than just Pokemon Go or Mario Run. If Nintendo can sell millions of NES and SNES systems in this day and age and that game play still holds up, 3DS is light years more advanced than that and those games are still perfectly fun to play.
If you can sell NES Classic and SNES Classic, I don't see the big deal is selling 3DS for a few more years. Offer more games on the eShop (DS titles should be brought onboard) too.
Switch meanwhile can focus on an older demographic.
