Yeah I have seen it go both ways with other players. Some are discontinuing running the mission and some are continuing to run it (either they already had enough fans or are buying more cards).
For someone just getting the millionaire card for the first time, it may be easier since you can keep buying the right kind of cards to keep the mission active. But I wasn't playing the game that way so I ended up in a real pickle that required a big additional outlay to keep it going.
Thanks for stopping by and have a great weekend too!
!PIZZA