I think he was trying to architect a design in which WhatsApp itself wouldn't be exporting the data over the network, which could be spotted through metadata an

I think he was trying to architect a design in which WhatsApp itself wouldn't be exporting the data over the network, which could be spotted through metadata anlaysis. Lower-visibility to slipstream it in with some bulk data. But yes it is an overly complicated mechanism for what would be a simple change by Facebook and one that people have raised here since the original announcement.