Just because Uber has settled two big disputes with drivers doesn't mean that its rank-and-file is happy. Uber drivers in California have partnered with the Teamsters Union to create a new group, the App-Based Drivers Association, to represent ridesharing workers in the state. Much like the (currently embattled) union in Seattle, this organization will push for better benefits and conditions among drivers that normally don't get much say.
The Teamsters effort won't affect the earlier settlements; Uber drivers are still considered contractors, not employees. Even so, it could put added pressure on the company to improve pay and perks -- workers could be more likely to walk off the job in droves when they're frustrated with conditions.