This is an issue for me as well. But it is also an issue for Kia.
No broad OTA capability on the EV6 when it is obvious a new system will soon be in place forces people to think. This is a core point in the value of the car. I think it will have a significant impact on the resale value. For me, buying the GV60 is the better option because of this rather than any luxury pitch. The EV6 suits me well otherwise, so a short term lease makes sense.
For several reasons, I believe Kia will move fast to the Nvidia system. A model refresh in a couple of years timetable is out of the question.
-1) EV6 is Kia's halo product and statement of future direction (all EV, competitive with 'upscale' brands).
0) It's already been announced their newly developed cars will use it.
1) The hardware/software is a decoupled component in the architecture, i.e. they can drop it in without changing motors, sensors, displays, etc. I don't know if a new controller system would need government agency recertifications. It doesn't seem to matter for other manufacturers.
2) The Hyundai group (and Kia) are trying to move upscale in the market. Broad OTA capabilities will become table stakes in the argument to spend more. Tesla has been selling that to the early adopters from the start. But it is not just early adopters who will respond to that idea. People now generally understand the importance of upgrades and improvements from their experience with smartphones and computers. In short, OTA capabilities will become a key differentiator and your product won't make the short list without it.
Choice in the attainable EV market is exploding now. Being early to market and investing to make the move to a technically advanced, more luxurious brand is critical for Kia. They have a small window to accomplish that. The Chinese manufacturers will likely soon begin to eat the low end of the EV market in Europe and North America. Most legacy automakers face an existential threat and for many the strategy is to move upscale and be competitive in that market with high volume. Not all of them are going to survive.
I will surprised if Kia doesn't move to Nvidia in the EV6 soon. They might even slipstream it into the current model.
They won't wait long in any case because it will be part of having a competitive product in 2023.