From a business stand point, Apple should release an iPT that's the same as the iPhone 6+, without the phone part, just like the old days.
The reason is Asia. Rich nations like the US are a small percent of the world market. The "phone" part of smart phones aren't used much and if not there, WiFi phones get the job done.
I think Google has announced a new WiFi phone service that could be a game changer.
Most people in the world live on something near $1/day, a 2 year contract for a phone just won't work for them.
In addition, Apple need all the market share it can get.
Apple's numbers are huge if you look at profit, if you look at market share, it's a different story.
If Android get it's act together concerning malware an more uniform product lines, they could change things quickly.
Once a platform is set, it's harder to get the user base to switch. If Asia goes Android or if the business world goes Android, it'll be hard for Apple to unseat that base.
The other issue is developers in low income areas, if they can't afford the devices to develop on Apple, they'll go Android.
The same thing goes for BB, Win, and Amazon. It's all about market share and being able to keep it.
The largest markets are not rich.