Apple is focusing on a 64-bit only future for iOS devices and software. Apps that do not play well with the latest architecture will cease to be supported in the next major release of the operating system, while 32-bit iPhones and iPads could get the axe as early as the next iOS 10 update.
How do we know that? Well, Apple just made the first iOS 10.3.2 beta available to developers and it does not include restore images for the iPhone 5, iPhone 5c and the fourth-generation iPad. All those devices are supported by iOS 10.3, which Apple released earlier this week.
Apple typically drops support for older iPhones and iPads in a new major release of iOS. Last year, when it introduced iOS 10, the iPhone 4S didn't make the cut, and neither did the third-generation iPad, the first iPad mini and the fifth-generation iPod touch.
So, normally, the iPhone 5, iPhone 5c and fourth-generation iPad would only get the boot from the list of supported devices with this year's release of iOS 11 (or whatever it will be called), which isn't expected to be officially available until September. (Next year, the same will happen to the iPhone 5s and the first iPad Air -- and probably other devices, like the second-generation iPad mini.)
There is still a chance that Apple will release the recovery images at some point, mostly because the company isn't one to surprise its customers like that. Apple is predictable in terms of when it releases new products and when it stops supporting older ones. Either way, we will keep you updated with new developments.