All four test files at the link above play fine for me in MC32 at their native bit-depths and sample rates. Here's a screenshot of the
audio path when playing back the 32-bit/352.8 kHz WAV file in MC32...
If it works or not without the need for dithering and/or resampling is all going to depend on what the audio output devices supports and how it's connected, so your results may vary. However I can say that over USB using my iFi ZEN DAC 3 all four files play fine.
the latest version 11.2403.5.0 of Windows Media Player can successfully decode and directly play those 3 DXD audio files (*.WAV & *.FLAC) without external DAC.
Because it's resampling them. I opened the three PCM files in Windows Media Player 11.2403.5.0 and it's definitely, absolutely 100% resampling them. My DAC informs me what sample rate it's playing at, and it's not going above 48 kHz so it
isn't playing back at native 352.8 kHz like MC32 can.
As I said before, Windows Media Player goes through the Windows system mixer, meaning it's going to dither and/or resample the audio without informing you so playback will always work. Windows Media Player isn't good for testing things like this nor is it a valid test as it'll always resample to whatever bit-depth/sample rate you have it set to in Windows' sound settings for the audio output.
You can achieve the same thing in MC32 by going into DSP Studio > Output Format and setting the output for 352,800 Hz to a lower sample rate like 48,000 Hz or 96,000 Hz or whatever the max sample rate your output supports. It'll play it like Windows Media Player does, but like Windows Media Player it won't be playing it back at the native 352.8 kHz.