I may be in the minority here but this is my take as a day 1 Wii-U lover.
I don't mind if Smash, Mario Kart, and Splatoon have so-called "enhanced ports". Those three games are excellent, well-crafted games. I love all three of them and play at least two of them on a weekly basis. If Nintendo brings these games over to the Switch day 1 or within the first six months, that would be a great start to the library. Obviously there would have to be some extra's like new characters/stages in Kart and Smash (maybe redo Battle Mode in Mario Kart too). Splatoon would need new features and maybe another campaign. Bring a slightly fresh addition to a great foundation and Nintendo would be off and running.
Personally, I would rather see Nintendo put minimal resources towards these ports and focus more on new experience (like older IP's or new IP's). I don't need a brand new Smash Bros game that will take three+ years to make and tie up resources that could be spent elsewhere.
That's where I'm at as well. On Wii U they needed years to check off the list with Mario, Mario Kart and Smash to then go on and do something fresh like Splatoon. Those games are evergreens and super solid. They are not like most Remasters on PS4 or XBO, those are SOME games remastered. In case of Switch those are THE games that need to survive Wii U's death. I could play Kart or Splatoon forever so having them on Switch right from the start with a good online structure would be amazing. And cool new modes and more content please. But not something like Bayonetta or Xenoblade. Those games don't need an enhanced port in my opinion.
Release those ports and then focus on all the cool new stuff. It will be glorious.