I think it makes sense to take a step back and ask yourself if Apple, or any sensible Western company, would set up a system that could falsely flag millions of people, or even a hundred. Even without going into implementation details, it seems clear that they would not have a system that would flag standard family photos.

I wouldn't over-/underestimate the support capabilities of a big corp like Apple.

I remember the Twitter account takeover hack a year ago, which was possible only because customer support had some 2FA-bypass: https://en.wikipedia.org/wiki/2020_Twitter_account_hijacking

To prevent false-positives, who knows if they have a "review" team that takes a tiny little peek at my naked son. Do you know for sure that no such system is in place or ever will be in place? What if they do get hundreds of thousands of false positives in the future? How would they improve their system if not by reviewing the existing system with real data?

They are not looking at your photos at all, they are comparing hashes of them to hashes of KNOWN predatory material. Your family photos will not be in that database.