Regarding iPhone's international warranty

There's never been international warranty on iPhones. a couple years ago, there were unsubstantiated rumors that Authorized service providers in India would be accepting iPhones bought elsewhere for warranty service, but there was never any confirmation from Apple of this and it remains an uncorroborated rumor to this day.

Currently there is no official Apple supported International Warranty on iPhones. Apple as stated in the warranty terms may and often does restrict warranty service to the country of purchase.

See here: Apple One (1) Year Limited Warranty

IMPORTANT RESTRICTION FOR iPHONE, iPAD, APPLE TV and HOMEPOD SERVICE.

Apple may restrict warranty service for iPhone, iPad, Apple TV and HomePod to the country where Apple or its Authorized Distributors originally sold the device.

I don't know how there can be an update on something that doesn't exist. iPhones do not have an international warranty. They never have. If you bought the phone in the U.S., you'll need to bring it to the U.S. for warranty services.