WhatsApp does the counting of message forward completely on the client side. Their server does not know how many times a message has been forwarded.
THe article author's point was not that metadata is being sent in the clear, but that the real goal of encryption is to be unable to manipulate social behaviour. And because WhatsApp controls the client, they are able to do this without breaking E2EE or leaking metadata.
THe article author's point was not that metadata is being sent in the clear, but that the real goal of encryption is to be unable to manipulate social behaviour. And because WhatsApp controls the client, they are able to do this without breaking E2EE or leaking metadata.