App Thinning and specifically On Demand Resources, sounds great but there seems to be an elephant in the room I haven't heard anyone address and that is, what about the extremely large percentage of users who don't have an always connected device? A very large percentage of iPads are not always connected to the internet, instead roaming from hotspot to hotspot, and there are even iPhone users who do the same.
If your app takes advantage of On Demand Resources then all of those people will be in a bit of trouble, which means as developers we will want to avoid that risk and instead I suspect many people will not take advantage of On Demand Resources which would be a huge shame as well.
Has Apple considered making the On Demand Resources work as an opt-in system for customers? In otherwords the developer uses it like intended, but the user themself has a global switch on their iOS device that indicates to the App Store that all apps should be fully downloaded, or use on demand loading.