It's public knowledge that DuckDuckGo has been creating exemptions for Microsoft for awhile. DDG openly says they are sending your user IP address & user agent to Microsoft for the DDG ads on-click.
But you won't find any public articles from DuckDuckGo explaining *why* they are not blocking Microsoft-owned 3rd party data flows on websites *not* owned by Microsoft, like on Facebook's Workplace[.]com domain sending data to Bing & Linkedin in the DDG "private" browser.
And you can see proof that the DuckDuckGo team *knows* that Microsoft's domains are crossite tracking vectors @ https://raw.githubusercontent.com/duckduckgo/tracker-radar/main/domains/US/bing.com.json… - that's the DDG feedback loop to help them populate blocklists.