I'm pretty sure the "official" deal is - no one who is not a hotel guest is supposed to park in a hotel lot for more than 3 hours. The reason being, even if they are there to eat at the hotel or like your scenario meet up with friends staying at the hotel, it'd be very easy for those people to use the hotel parking lot and take a bus over to a theme park in an attempt to bypass paying for parking. It's why they stopped having buses that go from Disney Springs directly to any theme parks. Now people who stay offsite have absolutely no choice...but to go to Disney Springs, walk or boat to Saratoga Springs, Old Key West or one of the Port Orleans resorts to take a bus to a theme park and avoid paying the parking fees. Why does the man make it so hard to stick it to him?
Anyway, will the guards at All Star have a problem if your friends park there indefinitely since AFTER ALL you're all going to Disney Springs which is also free parking so it couldn't possibly be that they're trying to get away with something for nothing? Meh, probably not. But probably isn't definitely. And if for whatever reason parking becomes so scarce that actual resort guests can't find a spot, or if one guard decides he wants to be a hardcase, there's no guarantee your friends won't have a problem.
How many people are in your party? It's possible you could get an extra parking pass - it's not unusual for two couples or other groups with more than one car to share a room after all, and they're afforded extra parking passes.
It's also possible you could meet your friends AT Disney Springs, you spend some time there, then either take the bus back to All Star OR drive you all back, where it would then be more likely they'll only be there within 3 hours.
Again, they'll probably be fine. But probably isn't definitely.