When it comes to mobile devices, Apple has always been conservative with new standards — we’ve seen it with Bluetooth, 3G and LTE — preferring to let new technologies mature before embracing them.
This article is similar to what I said when the iPhone 5s passed on 802.11ac.
But waiting another year for 802.11ac-enabled iPhones and iPads also means we’ll probably have to wait another year before we see widescale adoption of the standard in public hotspots and access points.
This is somewhat bad news for WiFi vendors, but this means that the mature 11n access points can be sold for a bit longer. I suspect we will see 11ac across the iOS lineup by this time next year. The Mac lineup (except the Mac Mini and the non-retina MacBook Pro) has 11ac across the board. I am happy that the new iPads did add MIMO, though.