The HN title is extremely misleading. It is currently "Apple CSAM Feature Debuts in iOS 15.2" but the website title is "Apple's Child-Focused 'Communication Safety' Feature Debuts in iOS 15.2 Beta" instead. This is for using ML to identify nudity in messages, not the feature for doing perceptual hashes of photos and comparing against known CSAM images.
The source for this "article" is MacRumors linked in its second paragraph, which frankly does a better job explaining this is not the same as the controversial anti-CSAM feature. It's also opt-in.