No they aren't.
What got me started on this was a posting I saw on YouTube, where a fellow had a HTL-HD (think that was the model) receiver and he connected it to his non HD set and he said and showed pictures showing that the digital HD channels were received better than their sister channels broadcast in analog.
There are severa homemade bow tie antennas made for receiving digital channels shown there too.
Since none of them are HD sets you would be fine with the ones that you can get with the coupon. Until you get a HD set there is no real reason to worry about a tuner that can output an HD signal.