Since nothing Taylor Swift ever does is small, her two-hour conversation with boyfriend Travis Kelce and his brother Jason Kelce on their “New Heights” podcast is a watershed moment for a media format that has already outlived the device it was named for. By Thursday afternoon, Wednesday night's talk had already been seen more than 11. 7 million times on YouTube. But that's only a fraction of its circulation — clips distributed on Instagram, TikTok, X and elsewhere have received more 400...