It's interesting that page has a qualifier (boldface mine) that seems to offer them an out. I think Tesla might fall back on that and say it's achieving "full self-driving" if it's able to take you on five minutes of your journey, hit some situation that needs your manual intervention for 30 seconds, then does "full self-driving for another 10 minutes", you spot a situation that you have to intervene for 5 seconds, etc. "Well, it fully self-drove you for 98% of the duration of your trip, so that's full self-driving in almost all circumstances".
Whereas most of us would disagree and define FSD as when both no attention and no action is required for the entire contiguous journey.