I didn't read that old thread, but I have read before that Tom Sena bought up the licensing to all those old names, but the companies didn't actually sell out, they let their licensing expire. He just came in and basically took the names and licensed them out since they weren't licensed at that point. Not sure if that's true, but it seems plausible. I've even seen the canyons referred to as "Rockaway Canyon".
I have a twin fin Canyon retro fish. Bought it dirt cheap used off some kid (was his first board). I wanted to try a retro fish for small waves to see if I liked it, and didn't want to plunk down a huge wad of cash. I'll tell you what, the shape is not bad at all. I'm sure it's a clone of someone elses shape, hell could be a clone of an old real Canyon from the Rusty era. Whatever the case, it's a pretty decent shape/outline. I'd love to say it sucks, but I can't, cus the board went well. I rode it from knee high up to overhead. The board I had wasn't really chunky for a retro twin. It was 6'2" which is long for a retro fish (I'm 220 lbs) but only 2 5/8 thick, and relatively foiled in the tail and nose considering it's a retro. There were no obvious flaws to the shape either. Very symetrical, no oddities in the shape or outline like I see on a lot of popouts in the shops. Guessing it was machine cut to pirated dimensions, and then just had some minor hand sanding.
The quality of finish craftsmanship is pretty poor. The glass is heavy, probably 6 OZ, but it's just weird. It's hard and kind of brittle. Little chips/cracks all over, but hard to the point where it doesn't pressure ding. Someone said perhaps they actually spray the resin on...who knows. It just seems different than a "non-popout" glass job. Both swallow tail tips broke off and had to be repaired, the leash cup ripped out as it wasn't installed correctly, and eventually one of the generic fin boxes broke out. Their pretty junky boxes and it had some stiff fiberglass keel fins. I'm big and can put my weight into a turn so it was probably destined to happen. In the boards defense though, it saw it's share of head high waves, and I was hard on it; It was chest-head the day the box gave out.
For me it served it's purpose. I knew after only a few sessions I really like riding a fish. I was able to take from it what I liked and disliked, and I've since had a custom made with tweaks in the shape/outline that suit me better. Now the Canyon sit's in my surfboard junkyard in the corner of the garage.
As far as popouts go, you could do a lot worse, but it certainly had some shortcomings.