Sure they can make a mandate but the grunts on ground will still get sent pptx files by their vendors.
How do you think currencies are established? By accepting chickens and cows in lieu of legal tender? That’s precisely the meaning of legal tender. This is the exact analogue thereof: information is required as value is required, information and value are required in a mandated standardised form, other forms are rejected a priori.
Sure, the government could force a format change if they really want to.