(Yes, I know, it sounds like I'm splitting hairs distinguishing between copyright maximalism and copyright trolling. Please, humor me.)
What copyright maximalists really want is an end to the legal protections for online platforms (DMCA 512 safe-harbor) so they can go after notorious markets directly. They already partially accomplished this in the EU. It's way more efficient from their end to have one throat to choke. Once the maximalists get what they want, platforms that want to be legitimate would be legally compelled to implement filters, ala YouTube Content ID. But those filters would apply to content that's published on the platform, not just things on your device. Remember: they're not interested in your local storage. They want to keep their movies and music off of YouTube, Vimeo, Twitter, and Facebook.
Furthermore, they largely already have the scanning regime they want. Public video sites make absolutely no sense to E2E encrypt; and most sites that deal in video already have a content fingerprinting solution. It turns out it was already easy enough to withhold content licenses to platforms that accept user uploads, unless they agreed to also start scanning those uploads.
(Side note: I genuinely think that the entire concept of safe harbors for online platforms is going to go away, just as soon as the proposals to do so stop being transparently partisan end-runs around the 1st Amendment. Pre-Internet, the idea that an entity could broadcast speech without having been considered to be the publisher of it didn't really exist. Publishers were publishers and that was that.)
That really depends. And is quite a strange, perhaps worrying, take.
Because, for many people, copyright strikes are the least of their problems.
Not that I disagree on it being an issue.
Democratic countries are much more of a danger because Apple has offices in them and cannot easily pull out of the market if they feel the laws are unconscionable.
I can guarantee that some industry bigwigs are salivating at the prospect of this tech. Imagine youtube copyright strikes but local to your device.