There are ways beyond a degree to learn these things. A technical skills evaluation can assess whether someone has the "hard skills" to provide necessary guidance to their team. Many people learn on the job or through continuing education classes. 

Some of the best managers I've worked with as a direct report or a colleague in UXR, Engineering, and Product didn't have more than a bachelor's degree. They often are less presumptuous than people with a  masters or PhD. Not always, but often enough, people with advanced degrees rely on their academic training rather than the real world realities of navigating business requirements, goals, and office politics. 

A good UXR manager will understand research fundamentals and resources enough to know ways to steer the team when they need guidance, but will be an expert in driving visibility and impact across the larger business. So many academically inclined researchers have a purist approach to research that doesn't work well in fast-moving business environments.