And heaer I thought I was the only person who just can't get enthused about their new MacBooks, knowing that CSAM could just get added at any point in the future without my consent.
CSAM is an abbreviation for "child sexual abuse material", so no, that won't (hopefully) get added without your consent.
Like a lot of apps, you don’t need to use Photos.app. They didn’t sneak it in without explaining how it worked.