If we look at the games the current Series X is running at 4k 60fps, its limited so i don't think the upgraded version is going to run the same games at native 8k if any games at all unless it can double the performance of the current Series X. Also, i don't see the average people using 8k displays anytime soon so why bother pushing 8k... It should push 4k to 60fps for all games and 120fps for the few but i think 60fps should be the goal with better graphics on par with PC gaming rather than 8k that will not be supported for most content in and outside of gaming for many years to come as 4k isn't fully supported as is.
In my opinion, i think TV's should push for 21:9 ratio and move away from this horrid 16:9 that most content shown on TV is a cropped image from a 21:9 image filmed natively with a camera near that ratio. My phone records at 21:9... Also, most people cant tell the difference from a 8k from a 4k at normal home viewing distance.