We also made some core architecture changes to the product to remove a lot of complex handling for unsupported devices and functionality that is now duplicated in core Windows operating system functionality. (blogs.windows.com)
Examples of unsupported devices include: — Galaxy Tab 4 and below — Galaxy S5 Mini and below — Nexus 7 2012 — Droid RAZR (andyemulator.com)
It allows unsupported devices like the Blackberry Playbook and the new Metro interface to Windows 8 to give you a full reading experience. (goodereader.com)