That may be true.
But what is strange is why WhatsApp did not simply suggest we all just get the Android app. It's on Amazon, so they could have easily proposed a migration process.
What they DID say was that BB10 did not "offer the kind of capabilities we need to expand our app's features in the FUTURE."
I'm really stumped by how they choose to handle this. Do they know something about the Runtime a year from now that we don't?