That's an interesting, yet opposite, correlation from the article.
http://www.theverge.com/2015/7/15/8965409/us-internet-access...
Of course it could mean that people living in broadband poor regions with poor cell service are the new 'unreachables'. They don't have reliable land lines, and their cell service is spotty. This in itself is a worrying theory as people with times of service unavailability are much more likely to remain in poverty, many types of jobs poorer people work have on demand scheduling where their hours are changed commonly. Being unreachable they may quickly find themselves fired.