I'm curious how Apple is going to limit this functionality to Europe. Will it just be iPhones sold in Europe? What about older iPhones then? Can I import a Euro

I'm curious how Apple is going to limit this functionality to Europe. Will it just be iPhones sold in Europe? What about older iPhones then? Can I import a European iPhone to American shores? Will it be just detected region? If so, what happens if I fly from Europe to America for a week? Does it apply to all EU Citizens regardless of where they live, like GDPR? If so, how is that enforced for EU citizens living in the US, or dual-citizens? What about iPhone users without an Apple ID stating their location? Can Apple be sued if they inadvertently cut some European users off? In which case, if they are forced to play it safe, how will they prevent sideloading in America? If they discover they can't prevent sideloading in America effectively, then what?