You can go ahead and file this rumour under "temporary solution".
People have been wondering if Apple will swap out the Lightning connector in favour of a USB-C connector on the next iPhone, mostly because the iPad Pro and MacBook line now use USB-C. But there has been no concrete evidence - so far - to suggest Apple will ditch Lightning.
In fact, Japanese blog Macotakara, which has connections to both the Asian supply chain and Asian accessory manufacturers, recently claimed the new iPhone models, likely releasing this autumn, might not contain USB-C ports, as previously asserted. But they could come with a fast 18W USB-C charger and a Lightning to USB-C cable. Keep in mind Macotakara first reported the 2018 iPad Pro would drop Lightning.
So, while Apple appears unwilling to get rid of Lightning at this point, it might be conceding a bit here, and helping out iPhone users. For whatever reason, it has been selling smartphones with the same 5W cube charger it’s offered for years, even though the latest iPhone models now support wireless charging and fast-charging capabilities. Apple's iPad Pro from last year also adopted USB-C and came with an 18W charger.
But, if you want that same 18W charger for your iPhone, you have to fork out $50 for it plus the Lightning to USB-C adapter. Not cool.
By shipping it with the next iPhone, Apple can keep the Lightning port while still allowing iPhone owners to charge at a modern speed and plug their phones into their MacBook laptop without needing to buy a new cable. Sounds like a temporary solution, right?