It is highly unlikely that Facebook can read WhatsApp messages. The reason I say that is that Zuckerberg said the couldn't, repeatedly and explicitly, to Congress. If there was any chance that they could, he would have either not said anything (the context would have allowed for that) or he would have dissembled. As he did numerous other times on other subjects.
As to benefiting from WhatsApp, I'm sure they benefited just fine. They bought it for the contact info from millions of non-Facebook customers that they could use to cross sell. Their growth in, for example, LatAm seems to imply that it worked ok.
As to benefiting from WhatsApp, I'm sure they benefited just fine. They bought it for the contact info from millions of non-Facebook customers that they could use to cross sell. Their growth in, for example, LatAm seems to imply that it worked ok.