When most other browsers on the market talk about tracking protection they are referring to 3rd-party cookie protection e.g., blocking them) and fingerprinting protection (i.e., restricting APIS scripts can use), and our browsers impose these restrictions on all third-party tracking scripts, including those from Microsoft. We also have a lot of other web protections that also apply to Microsoft scripts (and everyone else) that most browsers don't do, including Global Privacy Control, 1st-party cookie expiration, referrer header trimming, new cookie consent handling (in our Mac beta), fire button (one-click) data clearing, and more.
What this article is talking about specifically is one web protection that the major browsers don't even attempt to do — stopping third-party tracking scripts from even loading on third-party websites. See for yourself the bottom 'tracker content blocking' section of this audit site: https://privacytests.org/ios.html (scroll to the very bottom).
This web protection is a particular challenge to get right because websites can easily break when scripts that they depend on don't load, but because it makes for better privacy and faster page loads, we've taken it on while still trying to not break sites. As a result, it is far from perfect, as we can't block all scripts do to persistent breakage issues (which we try to workaround), and domains change all the time (and we continuously crawl sites looking for new tracking domains).
Though because we're doing this protection where we can, and also offer many other unique protections (e.g., Google AMP protection, smarter HTTPS upgrading, tracking protection for other apps in Android, email protection to block trackers for emails sent to your regular inbox, etc.), users get way more privacy protection with our app than they would using other browsers. Our goal has always been and remains to provide the most privacy we can in one download. And we have a lot more planned.
The issue at hand is all of our web protections apply to Microsoft scripts on 3rd-party sites (again, this is off of DuckDuckGo.com, i.e., not related to search) except this one around full content blocking, as we are currently contractually restricted by Microsoft there. However, this limited contractual restriction (about this one web protection) is the only one we have, and we have been and are working with them as we speak to reduce or remove it.
I understand this is all rather confusing because it is a search syndication contract that is preventing us from doing a non-search thing. That's because our product is a bundle of multiple privacy protections, and this is a distribution requirement imposed on us as part of the search syndication agreement that helps us privately use Bing results to provide you with better private search results overall. While a lot of what you see on our results page privately incorporates content from other sources (including our own indexes), e.g., Wikipedia, local listings, sports, stocks, lyrics, weather, quick answers, etc., etc., we source most of our traditional links and images privately from Bing (though because of other search technology our link and image results still may look different). Really only two companies (Google and Microsoft) have a high-quality global web link index (because I believe it costs upwards of a billion dollars a year to do), and so literally every other global search engine that wants to offer a search product competitive with Google for mainstream users, needs to bootstrap with one or both of them. The same is true for maps btw -- only the biggest companies can similarly afford to accurately map every neighborhood. And we are still a very small company relative to these companies -- literally on the order of 1,000 times smaller.
Anyway, I hope this provides some helpful context. I understand why people are upset with us on this, and we will do better. We're working on updates to our app store descriptions and other materials.
(Also FYI -- this was discussed extensively at https://news.ycombinator.com/item?id=31490515). This is also a somewhat misleading title since it's not about our search engine, which people would assume, and also as noted above Microsoft scripts are actually restricted in our browser a lot, so I would suggest changing it.)