No. The entire discussion only applies to images being uploaded (or about to be uploaded) to iCloud. By default in iOS all pictures are saved locally only (so the whole CSAM scanning discussion would not have applied anyway), but that tends to fill up a phone pretty quickly.
With the (optional) iCloud, you can (optionally) activate iCloud Photos to have a photo library backed up in the cloud and shared among all your devices (and, in particular, with only thumbnails and metadata stored locally and the full resolution pictures only downloaded on demand).
These are always encrypted, with either the keys being with Apple ("Standard Data Protection") so that they're recoverable when the user loses phone or password, or E2E ("Advanced Data Protection") if the user so choses, thus irrecoverable.
It seems to me that in the latter case images are not scanned at all (neither on device nor in the cloud), and it's unclear to me whether they're scanned in the former case.
With the (optional) iCloud, you can (optionally) activate iCloud Photos to have a photo library backed up in the cloud and shared among all your devices (and, in particular, with only thumbnails and metadata stored locally and the full resolution pictures only downloaded on demand).
These are always encrypted, with either the keys being with Apple ("Standard Data Protection") so that they're recoverable when the user loses phone or password, or E2E ("Advanced Data Protection") if the user so choses, thus irrecoverable.
It seems to me that in the latter case images are not scanned at all (neither on device nor in the cloud), and it's unclear to me whether they're scanned in the former case.
https://support.apple.com/en-us/102651