https://motherboard.vice.com/en_us/article/gykkem/iphone-usb-c-lightning-port-dongle

For Apple consumers, there is no word more viscerally upsetting than “Dongle.” (Besides, arguably, “Touch Bar.”) According to rumors from Digitimes that have rapidly spread, the 2019 iPhone may use USB-C instead of a Lightning port. If this comes to pass, current iPhone users are cruising for another Dongling. The one glimmer of hope: it could be the Last Dongling for quite some time (until USB-C is usurped as a standard, if that should come to pass.)

The move to USB-C would make sense, as it's already an industry standard, unlike the Lightning port and connector, which are proprietary Apple creations. USB-C is already the charging method for many MacBooks, and would streamline the process of charging an Apple device (iPhone) with another Apple device (MacBook) which currently requires a dongle.