That is, for Apple, perhaps a nice side effect of the change. But I don't see it replacing Facebook app ads ... I never "see" the Apple ads.
The real purpose of this change is to continue to drive home to Apple users, who are increasing aware of privacy issues, that Apple has their back. Anything else is gravy.
My opinion: follow the money. Apple’s publicly stated growth strategy is to expand services revenue. Taking this ad market from Facebook is part of that strategy. The PR is gravy. Apple isn’t the EFF.