As far as Cyberpunk goes, PS5 owners should get a reasonable upgrade. Xbox owners should expect nothing.
Here is Cyberpunk with the latest patch on the Xbox platform with the most users (X1/X1S):
Standing on a corner:
Walking through the city:
Driving while shooting:
After this, CDPR said they were satisfied with the performance of the game on these machines and quit patching them.
The following is all speculation:
CDPR spent a year getting the Playstation versions working with reasonable performance. Almost certainly because Sony yanked the game from their store. Microsoft allowed the game to continue being sold, so CDPR didn't bother with any optimizations. They know they have to deliver a good experience on Playstation, but Microsoft doesn't really care.
note: Ignore the version numbers listed in the screenshots. Both Techfuse and EADB indicated in their video notes that they forgot to update their overlay text. These performance tests were all from the latest patch.