I wouldn't say it is Peak Apple
Rather I would say that just as Tablet's caused a slowdown in the PC Market, Phablets or larger screen phones are causing a similar slowdown in the Tablet market.
People are now finding that their needs are being met by their smartphone. The need for the Tablet is slowly being negated.
In fact I am sure that Apple have already seen the writing on the wall with the rumored higher orders of iPhones made to their manufacturers, certainly if they really are launching two sizes of iPhone screen, one being 5.5 inch -- a phablet -- they are quite possibly expecting to canibalize the iPad Mini Sales. Those that would buy the Mini as a second mobile device may very likely only get the iPhone with 5.5 inch screen and be happy with that one device for all their needs.
When I switched from Verizon to T-Mobile I purchased a Nexus 5 simply because I was cheaper when paying full price for a device and I didn't want to pay a premium for another iPhone 5S.
In the 9 months that have passed I have found that I use my iPad less, the little 7 inch Samsung Tablet I bought gathers dust and is never used.
You just have to look at markets where Android Phablets are the sole internet device of the owner. They don't purchase a PC, they don't purchase a Tablet they just have their Phablet and they get by fine!
The market is just changing and changing faster.
In fact pretty soon I expect that the Smartphone market will slow down in developed countries where they, just as they did with PC's, find that their Smartphone does perfectly well for what they do and they wait much longer, or until their device fails, before they purchase a replacement.