If you read the article you’d see that per Microsoft this is due to them not wanting the liability of an administrator changing settings without the users knowledge, then the user either not receiving a prompt for a default browser or their selection being ignored, both of which would violate the DMA.
I’m not really sure how the DMA applies to corporate-owned machines, at what point is the administrator the user?
Now I guess you’ve got to determine whether or not you take MS at their word or not. The example of blocked software was a script that edited a reg entry, for administrators to use. How does something’s like the prompt built-in to a browser like FF or Chromium asking if you want to set it to be the default browser operate? If it’s through setting this registry key lolol well played MS. Is ignoring user input from an uncontrolled third-party application and requiring the change be made in the Windows settings themselves a dark pattern, or at that point is it just malicious compliance? Although for all I know that’s not how the in-application prompts update the OS default file handlers.