I would be very surprised if the encode/decode block has a reduced featureset compared to the XSX. The area savings would be far, far too small to justify the cost of not just copying the design wholesale.
In theory? Sure. It's an X86-based AMD SoC, and the Xbox OS is essentially a fork of Windows 10. But it lacks a PC BIOS, there's no way to get a bootloader on there, there's no way to get it to boot off USB for installing the OS, etc. So in practice? No way, Jose. Never happening. Given how heavily subsidized consoles are, allowing running ordinary Windows on these consoles would essentially tank the PC market - why buy a gaming PC for $1000 or $1500 when you can get a machine essentially as capable, running all the same software, for the price of the GPU in the PC?