@Samurai Edge in this case the Owner's Manual specification has been superseded as mentioned by @dabangsta and this was due to research and development by Ford to reduce the risk of this V6 engine with its internal coolant pump.
Ford also revised the fluid for my 2017 V6 which doesn't have the risk of the internal coolant pump, and that's what I stick with.
There's certain fluids and lubricants that I use Non-OEM such as brake fluid, engine oil, RDU and PTU oil, and some that I stick with the OEM such as the coolant where we don't have the specific chemical composition and the reason for Ford's revision.