This sounds as a great way to make funds for themselves as well without having to worry about how to make money or even getting bought by some bigger company like whatsapp did with facebook. The problem with free apps and so forth is that they are literally free so if they want to make money they have to either sell your data but how do you sell data on a whatsapp chat type thing ?
I agree they could have simply added support for using the major cryptos, which could have been a interesting feature to offer. But offcourse you can make much more money creating your own currency.
On whatsapp and similar i figure they sell some sort of service (or directly the data) where you can run your search for particular keyword. It could be used to see how many people talk or mention your product, quite a valuable information