Micro-USB
was mandated by the EU. That's a large part of the reason we even have a standardized charging port.
This has been enforced since late 2012 (in draft since 2008) and is the reason why Apple had to include the micro-USB adapter in order to sell in the EU.
There is no reason for speculation since facts are available on your friendly neighborhood wiki. What we're seeing now is that the law is updated to enforce USB-C, which has been accommodated for a while.
The intent is not to standardize on an implementation forever, but to make the industry agree on a standard.
