It seems to me that having done something twice in the past is a better proof of being able to do that something than speculation is.
That's not microUSB becoming compatible - It's having to add hardware inside the device which makes use of microUSB's pins. The Lightning connector seems to push that to outside of the device i.e. make the right cable/adapter and software and you can adapt to anything without requiring support from specific hardware inside the device. At least that is what he seems to saying and it'll probably take some more analysis and dissection (not to mention actual adapters) to support that assertion.
The implication of this article is that the Lightening port can be repurposed, without changes to the device's hardware, simply by providing a new cable and software.
If the iPhone5 doesn't have internal USB3 or HDMI or DP support, it can't magically gain it through the use of a new cable and new software. It's probable the iPhone6 will support all or most of those, but that's because they changed the device's hardware...