Great. I recently invested $3800 in an excellent, new iMac. Now I'm starting to wonder if I should have spent a couple thousand less for a barebones PC and installed my favorite Linux distro. It would have done 75% of what I needed, and the other 25% (music and video work)... well, that's the tradeoff.
If anyone in my circle of family, friends, and social network asks my advice, the formerly easy answer "Get a Mac, get an iPhone; you won't regret it!" is probably going to be replaced with something more nuanced ("Buy Apple, but know what you're getting into; here's a few articles on privacy....").
The CSAM detection technical summary [1] only mentions iOS and iPadOS.
If it does come to macOS it will be part of Photos.app, as that's the only way to interact with iCloud Photos. I would recommend you to avoid that app and cloud in general if you care about privacy.
If anyone in my circle of family, friends, and social network asks my advice, the formerly easy answer "Get a Mac, get an iPhone; you won't regret it!" is probably going to be replaced with something more nuanced ("Buy Apple, but know what you're getting into; here's a few articles on privacy....").