Did you even read the article? It explains the science of how dietary fat is used in the body, cites studies which find optimal numbers for each sub-process and provides suggested guidelines for each section as well as overall. To say the answer is “we don’t really know” is a really weird stance given all this information.

As an aside this is the Science community, please don’t leave frivolous comments which do not attempt to discuss the science or do not start a productive conversation.