I understand this goes against the current ethos but honestly, you can't provide an essentially free service and expect things to just keep running sustainably. Nobody has proven that a social network can be run successfully without advertising and analyzing user data. I wonder what Mr. Koum offered as a counter-proposal for keeping the lights on at what should be an exorbitant cost with their userbase. My guess is, not enough, if anything.
Note: I do not work for facebook, nor am I huge on any social media, although I am a "light" user of both facebook and twitter.