I wouldn't be surprised if they went with the Xavier NX chipset nVidia released two months ago. The thing is the size of laptop RAM (because it is on laptop RAM PCB) has 48 tensor cores, 386 Cuda cores (128 more than the switch) runs at 3TFs (1.3tfs from Cuda and 1.7tfs tensor), supports up to 8GBs of lpddr5, while only using 15watts. For just an upgrades, its about the same as when the 3ds got the n3ds upgrade. This would allow DLSS support as well as it having tensor cores. They could also go with the AGX model as its still small enough to fit in the Switch's form factor, which basically just adds more cuda cores and runs at 4tfs, but requires 20watts and produces more heat.
As for an actual successor, DLSS is definitely in (assuming they stick with nVidia) as DLSS uses the tensor cores to run the AI that upreses the games. Raytracing is hard to say. Even if they went with Tegra Orin, which is 7nm Ampere based, there is no guarantee that it will have an RT chip. Could it while running at 15watts? Die shrunk and placed into a Ray tracing unit sure. Would it be as good as other consoles at it? Oh no, not at 15watts. Even if a dev creates a game running at 720p, looking MUCH better because of DLSS, while using raytracing, you're looking at barely a gigaray and still running at 30fps. While docked it can use anywhere from 20 to 30watts, getting much better results, but RT would sap a battery so fast, you might as well not mess with it.
DLSS 2.0 is more of a post-processing effect that can be added into already created games as long as it works with nVidia hardware. OG DLSS the game's code had to be sent to nVidia for them to run the AI first and that took forever, so hopefully it's 2.0
How do you think it will reflect the next Wii U? Hardware? Both Wii and Switch proves you don't have to be the most powerful to sell well. Even prior to Animal Crossing, the Switch had already reached the 50 mil mark. Software? The Wii U itself proved that having 3rd parties on board doesn't always help. The Wii U actually had more 3rd parties on board than the Switch did at launch and in the first year. Hell, the Wii U actually got two Call of Duty games.
The Wii U's failure was due to very VERY bad marketing. People either thought it was a WAY too expensive Wii add on or didn't know it existed at all. Nintendo tried to use the Wii's name while not seeing that the Wii's sales had dropped in early 2010, no one played the Wii anymore. Naming the Wii U after the Wii was horribly dumb, not originally advertising it as a successor, actually showing gameplay off with the Wii's controllers up front, bit them in the ass so bad they had to release ads and statements saying it's not the Wii. It was hubris through and through. To repeat a failure of this magnitude, they'd have to do it on purpose.