Not forgetting that WhatsApp is encrypted, so Google can't get at people's private data - the lifeblood of the organisation.
So naturally they'll do whatever it takes to mitigate it or move people away, just like they tried with Facebook.
i.e. if a buy-out doesn't pan out, try to out-do them, if that doesn't work, then try to invade/fish the data by any other mean.
"We are willing to get it one way or another, with or without their deal!"
- Eric Schmidt, 2010 - talking about the failed deal with Facebook and capturing their data.