When people say too weak, they generally mean too weak even when downgraded. No one assumed that any PS4 game on Switch won't be downgraded anyway. But there's only so far you can downgrade a game before it fails to pass the acceptable standards the game is expected to meet. How many characters can appear on screen, draw distance, textures, effects, framerate, etc.
FF15 and 7:R on a hit portable console in Japan would no doubt be alluring to Square - which is why I don't write it off.
If they downgrade the textures, draw distance, and other assets in the realm of the same production value as Zelda, Xenoblade X or 2 - I think that's still a great port imo.
Square is already porting DQ11 in much the same way. Which is puzzling as FF port like this maybe would make more money.
I predict NX launches in 2017 - not 2016