Fair enough, but I don't even know if the 3DS and WiiU can play movies on those and I've followed the 3DS hacking scene a good while. I do know that hacked new 3DS can stream (record game footage) without additional hardware and that sort of thing. Also, in which case you probably want to buy a Switch now, and not use it/update it, since Nintendo likes to patch stuff out later on with their handhelds (they don't like people customising, even to the point where they charge for 3DS wallpapers/themes). And even so... existing platforms have had the support for that sort of stuff for a while. 3DS already does that with most ROMs, officially supporting a good many games on Virtual Console and emulating the ones that aren't officially supported (of course up to a certain point, no GameCube roms on 3DS).
The one thing that Switch users may struggle with is getting DS/3DS games to run on them since they are both dual screen/bottom touchscreen too.
Though some say... the Switch is already 'hackable'...