It wont happen. Spacex will just spend alk the government's money then say oops. We missed the target date, can we have more money.
Now, you could say they will change their mind when they run out of money, but frankly I would respond by pointing out that Elon really doesn't seem to be in it for the money, but rather despite the money.
"I do appreciate money and it is needed to invest in ventures, but I personally I'm not in it for the money. I can already buy everything I could want."
EDIT: I am just supporting parent post's claim that
"but frankly I would respond by pointing out that Elon really doesn't seem to be in it for the money, but rather despite the money."