I am also confused about this wording but I assume it refers to the duckduckgo-app on android devices. It would be blatantly anti-competitive if google would refuse the ddg app in their app store, solely because they compete with them in the search-engine market -- there are legal mechanisms against this behavior.
Agreed. And there are laws against this sort of thing, and the regulators are slowly but surely catching up to the fact that they will have to start actually enforcing them.