I kind of doubt Apple would retain legacy support for the iPad just because they have the space. If they are pushing a lightning/wireless future, they are probably planning to deploy/force that future on their entire device line.

Wonder if they're going to somehow get the FAA to change their opinion on bluetooth/airplane mode.

Is Bluetooth discouraged on airplanes? I thought it was just the cellular transmission that is limited in airplane mode.

Maybe. Macbooks have more room for ports too, but they only put one port on those.