Ari Shapiro , a veteran of NPR’s “All Things Considered,” has joined CNN as a contributor, and will co-host a new video podcast called “Engagement Party” alongside longtime colleague Audie Cornish. His hire marks the latest alliance struck between traditional news outlets and influential figures who often continue to operate independently in the media space. To be sure, news networks have long cultivated relationships with experts and analysts, but in the current era, they are seeking to