What the heck is there to test? iPads have already switched - this isn't unknown technology with some huge risk :p
* How does the phone react to the differences USB-C offers - does faster charging heat the phone inexcusably?
* What happens to the phone if the USB-C male end breaks, arguably one of my favorite parts of Lightning. I can replace a cable much easier than I can replace a port on a phone.
* How will consumers react to changing the standard? A lot of people had a lot of 30-pin accessories.
To name a few.
Why would that be the case? Why would apps need to know what kind of port is used for charging?