Well, it's semi-relevant, isn't it? Because it's only scanning photos that are being uploaded to iCloud Photos - they've just moved the scanning portion down one level.
If your photos never go to iCloud, they won't be scanned.
> So what's the point of doing this client side then?
Not a clue. Maybe they're going to make iCloud Photos fully E2E and this is the only way they can keep the CSAM scanning alive? Or maybe they just want to avoid it arriving on their servers at all (but I don't think anything has said matching CSAM photos will not be uploaded?) Or they just want to save some CPU on the iCloud side by punting that down to the phones themselves?
(Or, yeah, this is just the precursor to doing more client-side scanning and the slippery slope cassandras will be proven correct.)