I'm not sure I understand the motivation. Seems like they don't have much to gain and they do have a lot to lose.
While (anecdotally) Facebook doesn't appear to be very hype with the youth today, Instagram and WhatsApp still appear to be quite popular. In a weird way Facebook is both the mainstream choice and the underdog, that's a good position to be in IMO.
Beyond that what does it mean for people like me who use WhatsApp but do not have a Facebook account? Is the plan to force people like me to create a Facebook profile?
They /could/ do it quite easily. I can email people who have different kinds of email account with no problem. The Jabber / XMPP protocol was designed to link messaging systems in this way.
While it would be great if they moved to a pure Jabber federation model or similar, I very much doubt they will do that, however, unless someone like the EU can get their act together and force them to do it.
I think they would link all your accounts by phone number. This may not appear directly in the front end app.
Most likely though in the background they will use these links as ways to package your identity up when selling to advertisers. Thats what I'm guessing is the end goal , enrich their stagnant platform (FB) with their growth platforms (WhatsApp and Instagram)
While (anecdotally) Facebook doesn't appear to be very hype with the youth today, Instagram and WhatsApp still appear to be quite popular. In a weird way Facebook is both the mainstream choice and the underdog, that's a good position to be in IMO.
Beyond that what does it mean for people like me who use WhatsApp but do not have a Facebook account? Is the plan to force people like me to create a Facebook profile?