The Wii was what, a 12 Gflop console with 88 MB of memory with a single core CPU clocking at 750Mhz. Even with the lower resolution on Wii, its not like it was native 720p on 360/PS3, they were typically running 600p. A 2.5x difference in pixel count. Wii was a totally different animal than the 360/PS3, and because sales potential was there, they dedicated a 30+ man team at Treyarch to do the Wii ports. Framerate test on Youtue showed a pretty solid 30fps too. The performance difference between Switch and the other consoles is large, not saying its not, but its nothing compared to what they were dealing with on Wii. Again, follow the $$$.
Most games do not have the sales potential on Nintendo platforms to dedicate any significant resources. Its going to be a dollars and cents thing. I expect EA will choose to pass on most of their lineup. Games like Fifa and Madden and perhaps even Garden Warfare are what I see as likely candidates. COD on Switch is almost a given at this point. The series is on a decline, and they know they have been able to carve out a niche audience on the Wii, so I totally expect it to show up later this year.
I don't think any ps4/xbone big budget title is a given, they have to port it down to hand held mode, which only 200 gflops, and it's a nintendo console. i wonder if they will even bother, i hope we get at least one port of a big aaa title, but i have a feeling they won't bother.