Japanese Mac blog Macotakara posted a new report tonight which indicates that Apple will maintain the Lightning connector on the 2019 iPhones but may finally be including a 18W Fast Charger and USB-C to Lightning cable. 

"In addition, the next iPhone seems to continue to adopt the Lightning connector, but the charging cable has been changed to the USB-C to Lightning cable, and it seems that the attached power adapter may also be changed to the Apple 18W USB-C power adapter is."

The inclusion would represent an upgrade to the currently shipping 5W USB adapter. The 18W adapter allows fast charging with iPhone X charging from 1% to 79% in one hour. 

This rumor actually contradicts a previous report by the same site which expected Apple to retain the 5W adapter. Macotakara also reiterates Ming-Chi Kuo's report that this year's iPhones will have ability to wirelessly charge other devices. 

Source: macrumors