Actually, what they do is a good thing, although it may seem absurd at first. With this example if Windows Novosti which I mentioned - they promote Windows Mobile in the best possible way, and yet they needed to obey, and they respect the decision of Microsoft.
If a user searches for Skype, it would be bad if they allowed having Microsofts Skype as Skype, and for example "Skype for Windows Mobile" by another developer. Those two have got to have different names, there has to be no confusion which one is official, and which one is not. Same goes for Hangouts, even though we all agree it us not so likely for Google to release their own client for the service.
What you need to do right now is contact the developer, and you will know all the details. I am interested to know the details myself as I also had in mind to purchase this app.
Plus, what I said may not be the case, maybe they don't stay have any issue with their name, that was only my guess. But if it is the case, then the developers are to blame actually because they could simply update their app in the Store with the new name. Maybe they have removed the app from the Store themselves only until the change the came if the app, who knows...
Just ask them, and let us know what they said.
Sent from mTalk on Windows 10 phone