Honestly, I think the 3-minute video wasn't enough to get any idea of launch lineup, let alone the first year of releases. If I had to guess, I'd say Nintendo's dev teams are crunching as hard as humanly possible right now to get as many games finished and ready as they can. There may be a whole slew of things that just weren't quite ready enough to promise yet. We won't know until later.
I'm also not so sure that those games are going to just be ports, to be fair. The footage we saw of Mario Kart showed two item slots, a mechanic that MK8 didn't have, as well as King Boo who wasn't a character. That suggests that at the very least, the game was MK8 with significant changes / enhancements rather than a straight port. Possibly a new game altogether. It's impossible to tell with the amount of information we have though. Similarly, the Splatoon footage showed the ability to customize your inkling much further than what the original Splatoon had. You can change pants and hairstyles, and the map they showed isn't in the original game. So once again we're looking at *at the very least* a release with significant changes and enhancements, or possibly another game altogether. TL;DR we don't know yet, but signs indicate that they aren't straight ports.
I saw that too. Seems pretty dumb to sit on it for another 2 months, but I guess they don't want to take any momentum away from whatever holiday they have remaining. Pokemon and... uh... Pokemon. Yeah. I guess if nothing else, we may see some game leaks now that the first trickle has happened. But yeah, they're being very tight lipped about the thing, even now. Peoples' thirst is gonna get out of control.