All that I remember was that he helped with the implementation and that they have a functioning system that they consider correct.
I think he and everybody else knows the limits of the security model of WhatsApp. Just because they have a working setup, does not mean they are actually using it, or have not changed it without his knowledge.
His assertion was simply that WhatsApp was capable of offering the same service as Signal.
This is from memory, but I don't remember any 'PR tour'.
