I think the point he is trying to make is that the technically newest APIs (19/Kitkat) aren't all that different from any of the 3 Jelly Bean APIs in a significant enough way that the SDK can't mitigate the differences in an acceptable way.

http://developer.android.com/about/versions/android-4.4.html

All pretty reasonable for an API upgrade, and I don't think it's going to break legacy.