Wasn't this one of the main points of the Switch? GameFreak bullshitting again.
Heck, the Superbowl commercial is basically that with Zelda, seamless change between handheld and home console.
This is so ass backwards. There's nothing mechanically about the mainline Pokemon games that you would have to change to make it "work" on the Switch. He's making a big deal out of nothing, just have the same core experience with bigger set pieces and better model and resolution.
At no point did they say it couldn't work unless they changed the fundamentals of Pokemon, that's putting words into someone else's mouth.
You cannot deny, though, that the change to a device like the Switch means that they can't do things
exactly the way they were done before.
Hardware like Switch would carry certain expectations graphically that they've never been required to meet due to hardware limitations on GBA/DS/3DS, just for the obvious example.
But there's also things like, say, tabletop mode, where they may opt to design a multiplayer solution in instances where only one Switch is present, an option that doesn't immediately come to mind with a standard handheld device.
Also, they'll have to consider if they actually want to do anything with the hardware-standard 2nd analog stick, since that's not been part of Nintendo's standard hardware configuration on handhelds until New 3DS.
Just moving Pokemon as it exists now is entirely feasible, but there's facets to the hardware that they'll certainly want to determine if they want to do anything with, things that were not previously accessible to them in the standard handheld hardware configurations they've worked with before. All without saying that the scale of their work graphically needs to change and determining how they want to meet that challenge, either by growing their own team or bringing in another studio.