On the one hand, they're a capitalist business. Why should they get the labor of play testers for free?
On the other hand, a lot of people might like to do this if there was reasonable in-game compensation. It doesn't have to be a lot, but ... something. I'd still rather that playtesters get paid for the work since EA/CG is going to make money off their work, but with such a large fanbase if they offer this opportunity up with no pay there will be enough people jumping to do EA/CG's work for free that it's likely to at least make the outcome better. If people want to do it for free, I'm not going to stop them.
If they do do this, there would have to be another, private forum just for those playtesters to talk to each other. People could suggest crazy, off-the-wall ideas like using NS Zombie as lead against Darth Revan. Then a bunch of people can try it and we're likely to get better data about exactly when and how and how often those crazy ideas work. If it turns out that NS Zombie lead works 10% of the time on offense and never on defense, they can shrug it off. Yeah, it can win, but it's not a problem. If it works 90% of the time on offense and 5% of the time on defense, that's a real counter, and they have to decide whether they want to do anything about it. If it works 90% on offense and 50% on defense, that's a HUGE problem and needs a fix. But we can really only be sure of this kind of thing if we have a LOT of play testers all trying out a single crazy idea. And since there will likely be lots of crazy ideas, you'll need lots and lots of play testers. I don't know how many, but sure as heck it's way more than CG is using now.
...finally, I don't think the toons need to be made different colors: you would be logged into a separate test account, probably on a completely different app (obviously with a lot of shared code, but still a different app). There won't be any confusion.