5-8. Why not? These features could definitely be useful to some professionals as I mentioned. It would also make no sense to implement them in the Studio Display 2 but not in a monitor that is over three times more expensive. At that price, no excuses.
I've seen this discussed before; it's been indicated the target customer demographic for the Pro XDR is a professional one that wasn't looking for in-display speakers and some of the other features of the ASD, which while it can be used by some professionals seems to target both demanding home users and presumably a range of office worker types (and yes, some more graphics-heavy professionals). The Pro XDR wasn't for home users who just
wanted extra 'big and sharp,' but professions with access to deep pockets who
needed it for productivity. Some pro.s didn't need or want a webcam and especially not built-in speakers, and those who did might prefer choosing their own higher end 3rd party products rather than Apple's built-in (that you still have to pay for).
So your posts bring up an interesting issue; if technological advances make the Pro XDR less attractive at its high price point, what should Apple do? Some options come to mind...
1.) Somehow advance it in ways that might appeal to high end graphics-intensive professionals - like 8K and maybe go to 42", higher refresh rate, etc... Price would stay out of reach for most of us.
2.) Radically cut the price to compete with the newer 6K 32" displays that target a lower end demographic, including home users willing to go as high as $2,000 for a display. Not what I think Apple would do.
3.) Keep the price high but 'Studio-ize' it. So, the display would remain largely as it is now, but add built-in speakers with special audio, a webcam with CenterStage, etc..., but then the price would be way above those new competitors targeting a lower end demographic.
If they go for 1.), that is in the spirit of the original Pro Display XDR. If they opt for 3.), it would basically be a 6K 32" ASD more so than a 2nd gen. XDR.