In all likelihood, moving drivers from contractor to employee status will result in lower pay for drivers. Uber won't foot the larger employment tax bill. They'll just lower driver wages and increase customer prices.
More likely they will enforce the hours that the employee can work. If you are idling around at 4 AM in the burbs, they aren't going to pay you full rate, they will just kick you out and set working hours. If you don't like the hours, you get fired.
Less flexibility for drivers is probably a guaranteed outcome
