Earlier quoted context omitted.
Google pays Apple something like $9 billion a year to be the default search engine. So it seems unlikely.
Apple could use DDG as leverage though. If Google stops paying those 9bn, Apple has no reasonable alternative search engine it could resort back to. By quietly continuing development on DuckDuckGo for ~500mn/year, it could be some deterrence towards Google's monopoly that aligns with Apple's own interests.
And they'd be wise to avoid the Ted Turner mistake: when all your competitors are vertically integrating, don't be the last person left standing without a chair by the time they complete their integration. It leads to an essentially powerless bargaining position.
And like it or not, Google, Facebook, and Amazon are extremely aggressive about integrating their platforms. Microsoft being somewhat of an odder duck.