I’m not editing my statement above, but after researching this I learned that I’ve been given the right advice but the wrong reason for it. A better explanation is below.

The specific concern is that if you ask and they talk about living in a place that is primarily occupied by a specific protected class, you have now accidentally strayed into the danger zone of federal concern. Long commuters are not a protected class, but people are highly variable in their sensitivity to commute times. Since it does not specifically relate to their ability to do the job, experience, or other factors you should be focused on, you should stay away from it.

A safe question you can ask if you’re concerned is something like “our core working hours are N to M, will that pose a problem for you?”