Comment by detaro

The work you link is based on the NeuralHash code shipping with iOS and macOS, and explicitly says so, so there is no reason to theorize if it might already have been in a shipped OS - if it hadn't, we wouldn't have research about its abilities. (What as far as is known - and I suspect it would have been found by people scrutinizing the updates - has not been rolled out is code that actually uses it to implement the reporting mechanisms)