Yes, yes it is. It's players that figure out things that the dev miss and notice certain classes being over or under powered and making efforts to fix them.

On Blizzard's test server for WoW they allow players to test everything coming up, ALL the content, all the raids and dungeons, and allow players to use the numbers and gear to help the devs balance things, there's spoilers and all of the surprises are removed ahead of time. Know what? That's the way I prefer it, believe it or not I actually hate surprises. Especially when it comes to things like new abilities and numbers, I want to know EVERY change, EVERY number, EVERY mechanic, and all of that ahead of time so I know what to expect.

The devs need to stop being so restrictive and just let players in to test the content and use parsers to determine where things are messed up or don't work right. It's definitely a lesson they need to learn from Blizzard. If you don't want to be spoiled, fine, don't go on the PTR and don't read the posts about it on the forums. Keep yourself away from any sort of information you don't want, but for the rest of us? I say the devs should let us in to see what's up.