Update: A more precise translation has given a clearer idea of exactly where the "more powerful" version of the Nintendo Switch is at in development. Here's a segment, shared by USGamer:
"Beyond the smaller, budget-focused model lies the development of the overhauled next-generation model intended to replace the one currently available. Nintendo is believed to be experimenting on a number of different things for the device, including usability, improved image rendering, and changes to the operating system, among other things. One development source contends, however, that it still remains unclear at this stage who at the company will end up taking the lead on conceptual development for the new console."
The original story, with a correction due to the clarity brought by the above statement, is below:
A rumored upgraded version of the Nintendo Switch may still be in the experimental phases of development, and may not be ready to be unveiled as soon as has been previously predicted.

https://www.gamesindustry.biz/articl...chnical-issues