I imagine it would be a better tablet, hopefully it would also have complete backward compatibility. Edit: I see there are a lot of replies already on my comment but I need to add more thoughts to it, I have the feeling that if Nintendo is going to release a better tablet with complete backward compatibility with the Switch, most developers will continue to develop for the original console instead of developing games…
>complete backward compatibility That would mean Nvidia SoC. The first gen Switch choose Nvidia because they were cheap, and Nvidia were despite to get their SoC into some use. With today's Nvidia I am just worried Nintendo isn't getting any decent deals.
Reimplementing NVN is a big lift so NVidia certainly has the inside track but it's probably enough of a threat that Nintendo has some negotiating power.