What that means is Apple will permanently take full ownership and deny author access.
I consider all Big Tech to be agents of the federal government. If you have uploaded anythjng criminal, it gets sent to law enforcement. They can say otherwise, but I dont believe them.
No, it doesn’t. My Photo Stream was a little used service of the Cloud. So few people opted to use it that Apple is discontinuing it. There were easier and simpler ways of sharing photos than My Photo Stream that people opted to use instead. Unless you have a unique photo stored on My Photo Stream you are sharing that exists ONLY in that location, you are unlikely to lose anything. Apple CANNOT delete photos on your iPhone, and Photos you have stored in your iCloud account are also not going to be deleted.
Users who subscribed to My Photo Stream were notified directly from Apple to download any unique content they had uploaded to their accounts long ago. This is no surprise to the very few people who were possibly still using that service.
Apple now provides Shared Albums that essentially provides the same thing as My Photo Stream did back 12 years ago.