It has been rumored for some time that the iPhone 15 range will abandon the proprietary Lightning charging format to adopt the USB-C standard, in order to comply with the new European legislation.
USB-C on iPhone 15, “leaked” images
Reliable sources have come and gone to corroborate this major change, and the latest leak - by @lipilipsi and @John011235 on Twitter (or "X") - is none other than a photo of the attached USB-C connectors with flexible printed circuits, for several models of the next Apple smartphones: iPhone 15, iPhone 15 Plus and iPhone 15 Pro Max.
USB-C on iPhone 15, different transfer speed depending on the model
As a reminder, the new iPhone 15 Pro and Pro Max for the start of the 2023 school year would have at least USB 3.2 or even Thunderbolt 3 compatibility via this new USB-C port, but the "standard" iPhone 15 and iPhone 15 Plus models would retain the old USB 2.0 standard and therefore would not benefit from the new transfer speed of the Pro models.