What is the difference between pot roasting and braising?
Pot Roasting = Braising

This more recent document from the same association, Cattlemen's Beef Board and National Cattlemen's Beef, supports this by using them interchangeably: 3 Simple Steps For Braising/Pot Roasting Beef

I was trying to figure out what the document from your question may have been implying by the cuts the different cooking techniques were recommended for. And I'd guess, because Pot Roasting is applied to more connective heavy cuts, that braising would be a shorter cooking time. That's my best guess.