Windows Phone, unfortunately, has a lot of problems. It has a disadvantage in apps, market share, and phone selection. Today one of those problems looks to go away.
Windows Phone by itself is not very attractive to most OEMs. It has a small market, mind share, and less apps and services than iOS and Android. On top of all this, it used to have a licensing fee._Making OEMs pay to use a less popular OS doesn't lead to good things.