I somehow doubt they are going to have a major release every month, even if you include ports, and quasi-ports.
Zelda Breath of the Wild, Super Mario Odyssey, Arms and...?
Xenosaga 2 is clearly not going to happen this year. Splatoon 2 really doesn't look like a true sequel. Mario Kart 8 is just a port. However, even if you include them, what other exclusives are releasing? I just have a very, very hard time seeing this as "jam packed". Especially after we ACTUALLY experienced what a jam packed roster looks like this year with Sony's lineup (which, to be fair, is well into the console's life cycle, so Nintendo shouldn't be expected to replicate that kind of schedule). I would kick up a fuss if the wording had been "better than a typical console launch year".
I just think people are trying to spin a fairly thin year into something that it isn't.
Jam packed might be the wrong word, but we're still set for one noteworthy game every month since Switch release: May is only exception really. ARMS in June, Splatoon 2 in July, Mario x Rabbids most likely in August, Pokkén in September, and then for the remaining 3 months we still have Fire Emblem Warriors, Mario Odyssey and Xenoblade 2 slated. Not everyone will be interested in every game coming but it's a welcome change from Nintendo, since old consoles were plagued with dry spells of nothing. Hopefully year 1 line-up helps build the userbase and then 3rd parties will naturally follow.