From what I understand from his write-up, he's replaced several components with their counterparts from ReactOS (specifically the bootloader and the fallback video driver). Without access to the source code of the original OS and by using components from another, I'd call this an adaptation, rather than a true port. Your definition may differ, of course - and just for fun, I asked ChatGPT and it disagrees with me too 😂

The part I would call a true port is how he changed the ReactOS bootloader to work with the AppleTV - looking through the commit history on that is fascinating, I can recommend it if you haven't done so. Check it out at https://github.com/DistroHopper39B/reactos/commits/AppleTV-D...

To be honest, I'm actually more impressed by how he got XP to work almost entirely unmodified than if he had done what I would consider a true port of the full OS.