Perhaps this article might have been the impetus for the letter to Apple. from https://wccftech.com/usb-c-on-iphone-15-will-limit-data-speeds-on-cables-without

Perhaps this article might have been the impetus for the letter to Apple. from https://wccftech.com/usb-c-on-iphone-15-will-limit-data-speeds-on-cables-without-mfi-certification-compatible-accessories-underway/ https://wccftech.com/usb-c-on-iphone-15-will-limit-data-spee...: "Despite Apple's goodwill to bring USB-C to its iPhone lineup later this year, not all cables will be compatible to transfer wired data at maximum speed. You will have to buy an MFi cable or any other accessory with the standard to make use of the USB-C port's full potential. It was coined by ShrimpApplePro that this year's iPhone 15 models will come with USB-C with MFi."