Or put another way, if their browser had no content blocker (like the stock browsers of any mobile OS), their browser would be behaving like all the others. The scrutiny came from the conspicuous exclusion, given their arrangement with Bing (much like the controversy of Adblock Plus many years ago).
Yes, they block other tracking scripts, but since they have an explicit exception for tracking from Microsoft, it's not a complete stretch to say they were "tracking for MS"; I know technically it's Microsoft doing the tracking, but DDG gives them explicit permission to do so. I think that it's a distinction without much of a difference, and I don't think it's unfair to extrapolate a bit. If they're being misleading about the types of tracking in their mobile app to make Daddy Microsoft happy, why the fuck would I believe their claims that their search engine (which is more or less a proxy for Bing) would be immune from it?
It actually really upset me; I was a big user and advocate of the DDG browser on iOS and Android, but when that news came out it felt like a big betrayal. I haven't used any DDG product since then, and while I have no idea what kind of trackers they block (if any), I just use Firefox Focus now with Kagi search.
This rando's comments (https://old.reddit.com/r/privacy/comments/1bmubkd/thoughts_a...) on the filter bubble problem seems like a reasonable concern too. It's best for a search engine to know nothing about you and just provide the best results for what you asked, not what it thinks you want to hear.
The context of the news was a security researcher conducting an audit of the app. If DDG were, as the GP claimed, performing tracking on behalf of MS then it would be more concerning since there is a difference between performing tracking on behalf of a third-party company and merely excluding them from being blocked via a content blocker that most mobile browsers lack anyway.
A mobile app has much more freedom to do what it likes so if this was the worst that occurred in an audit I'm not of the opinion this mark against them is enough to change my use of them. Many things carry some compromise so one has to weigh if an alternative is better. Use of Firefox by default has Mozilla tracking (hence why some mobile forks exists, including one I use), analytics for sponsored links, non-disableable domain name auto-completion by partners, while use of Kagi search is directly tied to an IRL identity via payment.
For me, I'm comfortable using uBlock Origin on both Desktop and Mobile (via a Firefox fork) unless more egregious facts present themselves.
