Certainly, wind roar is the most prominent noise in my GTV8 at motorway speeds. My straight-through exhaust makes its presence felt when accelerating hard, but at cruising speed the engine is remarkably subdued. But at 70 - 80 mph it is hard to listen to the radio due to the wind noise. I'm not convinced that putting frames on the drop glass would make much difference. The author talks of the glass lifting off the rubber seal at speed, but that has never happened with my car, and my windows can be wound right up without difficulty at any speed. I have recently sold an Elan Sprint fixed head coupe - that has framed windows but suffered from wind roar in much the same way as the BGT.
No, I think the wind roar is due to the multiple protrusions that exist on the body work. the rain gutters, the quarter-lights, the projection of the B pillar, the door mirrors, the wipers, and even the rubber seal of the windscreen. Look at any modern car and the glass area presents a very much smoothed profile, the wipers are often tucked behind the bonnet edge, and there are no rain gutters. Even the door mirrors are a smoother shape.
The design of the body goes back to the middle 1960s and I'm sure it was designed to look right without much thought to whether it could slip through the air soundlessly.