Wait really?
Best I could find was this arstechnica article from 2022:
Microsoft trackers run afoul of DuckDuckGo, get added to blocklist: Search privacy company still needs Bing, but won’t allow Microsoft’s trackers. https://arstechnica.com/gadgets/2022/08/microsoft-trackers-run-afoul-of-duckduckgo-get-added-to-blocklist/
deleted by creator
Yeah that would be it:
Previously, we were limited in how we could apply our 3rd-Party Tracker Loading Protection on Microsoft tracking scripts due to a policy requirement related to our use of Bing as a source for our private search results
I couldn’t remember the details exactly, but basically up until then they were allowing Microsoft tracking despite all their advertising claiming they wouldn’t track users.