It really all comes down to if Apple has and is willing to maintain the effort of human evaluations prior to taking action on the potentially false positives:

> According to Apple, a low number of positives (false or not) will not trigger an account to be flagged. But again, at these numbers, I believe you will still get too many situations where an account has multiple photos triggered as a false positive. (Apple says that probability is “1 in 1 trillion” but it is unclear how they arrived at such an estimate.) These cases will be manually reviewed.

At scale, even human classification which ought to be clear will fail, accidentally clicking 'not ok' when they saw something they thought was 'ok'. It will be interesting to see what happens then.