Respect for your privacy is coded into our DNA, and we built WhatsApp around the goal of knowing as little about you as possible: You don’t have to give us your name and we don’t ask for your email address. We don’t know your birthday. We don’t know your home address. We don’t know where you work. We don’t know your likes, what you search for on the internet or collect your GPS location. None of that data has ever be…
"You don’t have to give us your name and we don’t ask for your email address. We don’t know your birthday. We don’t know your home address. We don’t know where you work. We don’t know your likes, what you search for on the internet or collect your GPS location. None of that data has ever been collected and stored by WhatsApp, and we really have no plans to change that."
Great: they don't take my PII - but a person can easily be de-anonymized with just meta-data.
In addition, nowhere does it say "we won't read your messages" or "we won't sell your conversations". I think they are interested in much more than just meta-data. If I were Facebook, I would be licking my chops at the prospect of access to the mountain of saved private conversations.