re: What happens after
It's not the first flight that will determine whether or not it will be a Flag and Footprints mission, but the later ones.
However, there will be later misions IF what is found on the first one (or earlier) will convince those who have the money to keep going to Mars.
The Moon was abandoned but it wasn't because of the successes, but because of its short term impracticality.
Raoul