They've been using them, too. Auto OCR so selecting text in images Just Works, image enhancements, Siri. I'm sure LLM Siri is in the works. Scanning your photos for CSAM. Let's hope that last one is more reliable than Siri :/
They added it back in as an optional thing for child accounts managed in a family in messages. It sure sounds like it's AI based and not hash based in this case.