Yes, that would be technically possible. But it will not happen because of how the incentives are set up. If Uber now has to bear the cost of being an employer, it will need to exercise its power over the employee drivers and force them to work.
Well, 'need' can be synonymous with 'not burn money in a way that leads to bankruptcy'. Uber is largely an uneconomical business that won't work if they end up having to keep their <10 hours a week drivers AND pay benefits.
