They needed the FB acquisition to supercharge their wallets, needed the pound of flesh to be demanded for the price that was paid in order to revisit their original mission, and now we're seeing Acton at least refocus on easy-to-use encrypted communications via Signal and potentially other platforms. The FB money has allowed for potentially more investments in the privacy tools sphere, if Acton continues his work in that area.
Whatsapp is a massively dominant messaging service, but the drive for privacy amongst consumers will continue to increase. It'll be interesting to see how we all communicate with the next evolution of all these apps in 10 years.