That being said, Apple is hoping to push the 64-bit system and according to a recent post on the Apple Developer website (via AppleInsider), Apple is asking developers to ensure that all their apps have 64-bit support by the 1st of February 2015, which basically gives developers about a little over three months to get their apps updated and ready with 64-bit support.
According to Apple, “Starting February 1, 2015, new iOS apps uploaded to the App Store must include 64-bit support and be built with the iOS 8 SDK, included in Xcode 6 or later.” As it stands, the iPhone 5s, the iPhone 6, and iPhone 6 Plus are the smartphones from Apple that have 64-bit chipsets.
As far as tablets are concerned, this will include the iPad Air, iPad mini 2, iPad Air 2, and the iPad mini 3, and presumably all future iOS devices as well, so we guess it makes sense for Apple to get developers to keep their apps updated to prevent potential issues from rising up in the future.