In “Who Invented Velcro?” CKDextHavn writes: “David Letterman put Velcro in the national spotlight when he attached himself to a hook-and-loop wall . . . [description of the proliferation of Velcro applications deleted] . . . By 1978, De Mestral’s patent expired . . .”
I think your chronology is a bit twisted. Letterman’s late-night talk show didn’t premiere until the early '80s, long after the patent had already expired and Velcro was everywhere.
CKDextHavn also writes: “There was fear that the term ‘Velcro’ might lose its copyright . . .” That’s trademark, not copyright. Names cannot be copyrighted.