In the end I don't think it will matter, Uber and Lyft could probably code around this pretty easily if it started to affect their bottom line. When they see 100+ drivers in the same place go offline within X seconds of each other, it's a pretty clear indication that there's coordinated action taking place. They probably have enough data from drivers' phones to see that they're sitting still waiting to go back online.
I just hope they don't decide to make an example out of these drivers by banning them...