Wow. Lots of opinions here. Here's mine. I do not think allowing two males to spar or fight or whatever you want to call it and put it on YouTube is a good idea. I do think allowing two male Jacksonii to see each other and get excited IS good for them. Let's face it besides getting worked up over seeing another male or getting jiggly with a female their lives in a cage probably suck. Does anyone think about what these guys go through to get here? They get caught, thrown into cages with a bunch of other males and females, shipped long distances in poor conditions, housed together at the importer, then at the dealer, then at the pet store....Do you think they fight during this time? Do you think they are supervised? Have you ever seen Jackson's missing eyes? All scarred up? Bite marks?
As I said I don't condone what the OP did but there are so many things that happen to these guys that are far worse IMO.
Comparing this to dogs, cats and birds is ridiculous IMO. Those animals do serious damage to each other. I have never seen a Jackson with injuries from fighting. Can it happen? I'm sure it can and does sometimes but injury and death are probably rare occurrences during these encounters.
If you think having two males interact is stressful to the chameleons then stop putting your Panthers in front of the mirror or in front of another male.
I wouldn't do what the OP did but I have put two males together and I've let them touch horns but for me that's as far as it goes. I see no point in letting them duke it out.
My opinion on the breeding thing is, if I had a group of males and I wanted to pick one to breed with a female I would pick the one that had the most desirable traits like coloring or body size not wether one could flip the other over on the grass.
As far as animal abuse, well this is a matter of opinion. No damage was done, no blood was drawn. This is something that happens ALL the time in a natural setting, so in my opinion it's not, but it is pretty uncool and not something you need to show off.
This is a touchy subject. People get really kooky with thier pets. I'm sure there are people on here that love thier chameleons more than some of the humans in their lives.

A little common sense goes a long ways.