Rumors are circulating on the Chinese social network Weibo that Apple wants to develop a special chip for the USB-C port on future iPhones. This would allow Apple to keep a grip on accessories. 
Gonny van der Zwaag | iCulture.nl – 12 February 2023, 8:30 whatsappfacebooktwittertelegramlinkedinmailprint
Now it is still the case that Apple can determine whether an official accessory is connected using a special chip for the Lightning port. As soon as Apple has to switch to USB-C ports, it will be a lot more difficult, since it is not its own standard. But Apple would have found a solution: the Lightning chip can also be used in future iPhones, so that Apple retains control over the ecosystem of official Apple accessories. Apple may block certain functions when connecting an unapproved cable.
Apple also earns money from the Made for iPhone label for accessories, which may only be used if a license fee is paid. This is not specifically tied to the Lightning port, as there are also game controllers and hearing aids with usb-c.
A special chip for the USB-C port can be used to allow fast charging or higher data speeds, for example. The fact that Apple also wants to make a special chip in this case can also have good intentions, for example to ensure that people who have bought expensive MFi accessories can be sure that certain functionality will continue to work. Apple is rumored to have developed an integrated circuit board that is compatible with Lightning and works together with the USB-C port on the iPhone 15. In this way, firmware can be used to determine what happens to the USB-C port is possible if you connect a cable or other accessories.
Now with Lightning connection, but maybe soon too with USB-C: the AirPods charging case.
Apple has already announced that the company will (reluctantly) comply with the requirement to support the USB-C port from the end of 2024. Whether this is already the case with the iPhone 15 remains to be seen. Apple has been using USB-C for some time in other products such as the iPad, MacBook and Apple TV remote. As far as is known, no chip is used that limits certain functions.
See also 
Apple CEO confirms: 'iPhone gets USB-C'
Apple CEO Greg Joswiak has confirmed in an interview that the iPhone is making the switch to USB-C. It has to be, under pressure from the EU.