Veteran host says format may not last as The Late Show with Stephen Colbert ends its 33-year run amid controversyAhead of the final episode of The Late Show with Stephen Colbert on CBS, former network late-night host David Letterman said that he would be “surprised” if other shows in that format last too much longer.Letterman, 79, made the remark in an interview with the New York Times that was published on Tuesday, in which he also described his “disbelief” upon learning Colbert’s show had been