Holiday is important. Summer is important only in that switch can't lose momentum. But I don't think it will. As for how well it will do, I just don't know.
Well, this is new.
I hate to say it but they already failed their first real test and that was the event yesterday. They showed 2 games that people really want (Mario Zelda) and some boxing dodging game? Yes there were other things and Splatoon 2 was interesting. But they could have shown one game and would have recaptured all hype. Metroid. They should have a reveal trailer along the lines of FF7:R. Didn't have to be much. But a simple trailer like that would have lit up the internet.
Instead we got some ice cubes and dudes staring lovingly into each others eyes instead of at a screen. Outside of Zelda and Mario, it wasn't good.
...I don't think Metroid particularly sells well... Nor even popular as many people seems to think.
Personality, for NSwitch, Summer Season must be capitalized instead of Fall. After all, Summer Season is where they can actually sell on this 'Portable, Anywhere Console' sales line.