Nothing that was quoted stated that. It is the endpoint that determines if native DSD is possible, not the core. In the above 2020 quote from me, the context was in terms of plugging a DAC directly into a ROCK NUC or Nucleus via USB.
Linux and native DSD playback can be complicated. Linux, like MacOS, defaults to DoP for DSD playback. For native DSD, the Linux kernel on the endpoint needs to be patched for the specific DAC. That means that if a user cares about native DSD, he/she should do research to verify that the Linux kernel that their particular device is running has been patched for the DAC they want to use to avoid unpleasant surprises.
For example, you are using an UltraRendu, there was a page on another website that detailed what DACs the Rendus had been patched to work with. Certainly not every DAC made.
Windows is “easier” since most manufacturer’s include ASIO drivers which are easily loaded, as compared to trying to get a manufacturer to patch a Linux kernel.
For example: See this post by Spockfish, RoPieee’s author on the subject
He was willing to work with an user to get RoPieee patched for a specific DAC. Not all manufacturer’s are so open and generous. Hence, the need to do research.