any changes in hardware, even it is a stubble in nature would mean amendment to production line process, change in BOM(bill of material), change in hardware based intrinsic factors, etc. etc. it's fine when you see these changes from few units perspective, but when you calculate for 3K-5K units, the additional cost could be substantial i.e in millions of $. Nintendo was careful to revise switch in terms of OLED, and few non-prominent features for the new switch version. They knew that these changes won't impact their expenditure forecasting, and these will run most of the switch exclusives at cost of certain graphical compromises, occasional glitches which the users won't mind much.
Switch hardware has aged worser than any 2-3 Years old anroid phone.. even a 2019 adreno GPU is more capable than a switch Tegra.. What makes it score well is the game optimizations.. Nintendo's devs are excellent in these.. you may see witcher 3 arrived to switch, which literally was not possible considering hardware limitations of switch. people were happy playing Witcher 3 in switch, and these racked more unit sales.. They didn't mind the graphical let-down when compared with switch vs pc vs ps4/xbox versions.
With the influx of recent handheld consoles in market, Nintendo will be careful to launch their new version.. what if it fails? I assume all the new handheld like steam deck, ayaneo etc, are also reaching Japanese market.. It will be interesting to see on what costumers will decide between the next gen switch or third party handheld consoles in near future? They may get both, or they might stick to handheld where you can emulate switch and do much more..
Nevertheless, the prevailing reputation for nintendo in Japan is quite good and they know that their fan base won't be fading away any time soon. Whatever get's them money and maintain their monopoly in the market is what they will follow as for now. They don't care on what else is going outside of japan and what are the needs..