'These features are coming later this year in updates to iOS 15, iPadOS 15, watchOS 8, and macOS Monterey.'
So yes.
Also by the OP:
> iMessage encrypts messages end-to-end by default; however, if you have iCloud backup turned on, your messages can be accessed by Apple (who has the keys for iCloud backups) and, by extension, law enforcement with a warrant.
So if you use iMessage and iCloud Photos then they will be scanned by Apple. Won't be surprised to see the on-device scanning feature more prevalent on M1/M1X Macs.
So if you use iMessage and iCloud Photos then they will be scanned by Apple--> it is a lie.
This is definitely not the case.
Yes, with iCloud backup turned on, messages can be accessed by Apple, that hasn't changed, has been the case for a decade. It is specifically written in the technical document that they are not scanning the iMessages photos in the cloud the same way that they would scan your iCloud photos.