Not sure about the exact numbers, but there is one thing to keep in mind: a significant part of those users were in "developing markets", where the fee was neve

Not sure about the exact numbers, but there is one thing to keep in mind: a significant part of those users were in "developing markets", where the fee was never introduced in practice. WhatsApp kept granting free extensions to them until they ditched the paid plan completely. I think that their next billion or two users have also been mostly in markets that wouldn't have been subject to the fee anyway.