I don’t think that effort was abandoned. And it’s not “scanning” in the sense you imagine.The good news is that I think any pictures of your honey holes are safe! I think Apple proposed some sort of ability to scan iCloud pictures to find and report CSAM, but I think that was abandoned.
Nerd: every image, file, etc has a unique hash that can be calculated using specific algorithms. In this case it’s MD5. A few non profits as well as governments and corporations have a records of hashes that resolve to csam. What apple does is cross reference the hashes associated with the images on your phone to the list of csam hashes.