I you want to use the 5 hours free content, you should get an Android/IOS device. The fact is that even Microsoft is starting to drop support on some of their windows phone apps, Skype for Business is a good example. I use both an Android phone provided by Fido and an unlocked Microsoft Lumia 950xl. If I was to use the 5 hours of unlimited download I would use my Android phone.
Don't expect businesses to support a dying o/s, even if it's a good o/s.
Welcome to the Community!
For the time being, the new Data Bytes feature is only available with Android or iOS devices that have the latest update of the Fido My Account app (version 3.1 on Android and 3.1.1 on iOS).
Note that for Android you need to have the operating system (OS) version 4.2 or higher and for iPhone you need to have iOS version 8.2 or higher.