My thoughts on the Switch and Pokemon is weird. GameFreak does their own weird stuff with Pokemon Games, so I'm not surprised that the 7th Gen is on the 3DS. Nintendo has also stated that the Switch will not replace the 3DS. Honestly, I wouldn't be surprised if GameFreak tries to stay on the 3DS for as long as they can. First, there's the issue of a lack of a second screen. It's possible to do without, but they'd throw away all the neat stuff they've had with the second screen. Also, the Switch's graphical quality is a HUGE step up from the 3DS's. Going from the 3DS would be like stepping from Gamecube to the Switch!
All of this just concerns me with the Switch. If the Switch did replace the 3DS, it would be good in that all games would be developed for a single Nintendo platform, but the bad would be the huge graphical jump developers would have to take, especially those who exclusively developed for 3DS.
On the other hand, assuming the 3DS isn't replaced by the Switch (which is what they said wouldn't happen), it would be good in that developers would not all be forced to use the high graphic, single screen console for their games. However, the bad would be that the splitting of games between two console would still exist. It just wouldn't be handheld games and console games, it would be handheld games and hybrid games. So for those without a 3DS or those without a Switch, if a game comes out for one that you don't have, you're out of luck unless if you buy a whole new system.