Mobile apps expanding to contain chat

I think this could be restated for mobile applications as:

"Every mobile app attempts to expand until it includes chat. Those applications which do not are replaced by ones which can."

I want to think this is a great idea, but from my experience of the new Evernote Chat (as noted by others in the know), it's not always a great thing. Another challenge? They're all separate silos - how (and why should) I remember where I had that chat conversation that I need to look up now? It's not a common occurrence but you can bet it'll be a headache the day I do need to look up that old chat thread..... An amusing irony of the spread of OTT apps is the spreading out of our data across a multitude of locations and services....

However, don't think chat is still open to change? Even Facebook is still launching different types of chat apps

Want to extend your thoughts on where chat may go? Read on....

Moreover, why should it only be explicitly social apps that access the phone address book to find my friends? Why shouldn't a retailer's app tell me that I have 8 friends using it, and let me share products with them rather than emailing them dumb, untracked URLs or even, quite probably, screenshots of my smartphone with the app open?

In other words, WhatsApp, Instagram and a dozen others have unbundled Facebook, but at what point and in what ways does WhatsApp itself get unbundled?