When ABC’s “Good Morning America” beat NBC’s “Today” in key ratings for the first time in 17 years the week just before the Olympics, there was another, less-measurable, indicator that “Today” could be losing its edge last week. Linny Boyette — the enigmatic superfan who’s shown up on “Today” daily for 20 years — popped up at “GMA” when “Today” began broadcasting from London. “He has been there every morning this week,” one ABC insider told us, adding, “we’ve seen him both on- and off-camera.” Boyette even posed for a pic with Lara Spencer, Josh Elliott, Sam Champion and Amy Robach. Ripples were mostly made on a Facebook fan page devoted to Boyette. But it remains to be seen where he’ll wind up post-Olympics.