Don't try to figure out Apple's product line anymore. Here we are over two years later, and you still can't plug an iPhone into a MacBook without an extra purchase.
While true and somewhat amusing, that's also a use case that hasn't really been that relevant to most people since iOS 5.
I doubt they'll touch the iPad mini again, and the non Pro iPad is the new plastic unibody MacBook from 2009 or the 2015 MacBook Air - it will live on, without hardware updates, for years - school systems need that kind of stability.
The non-Pro iPad is just over half a year old.