"People are asking to be able to go back and play WoW Classic as it was," Birmingham said. "We wanted to create this, almost like a snapshot in time, but we do want have these progressive content unlocks. So things like, Blackwind Lair, and Ahn'Qiraj, and Naxxramas. We want those to unlock over time, as the community is ready for them, as they progress through those various pieces of content. At the same time the systems overall we want to lock in at 1.12, where we feel like they were the most complete and balanced."
One player said in a comment posted in response to the list, “Yeah people don’t realize the sheer enormity of game system evolution WoW has gone through since release. I’m not the biggest fan of BoA by any stretch, but I’ve played since closed beta vanilla, and I doubt I’ll be going back to classic. Leveling was painful. Experiencing these old systems once was enough.”
One may think that the AH may suffer a reduction of competitivity, leading to higher prices, but in an healthy server the gold farmer's farm will be taken over by actual players. Giving the chance to a more fair gameplay where you can go out and farm the materials that you need, instead to see them always farmed by gold sellers that sell them to you, without letting you many room to make gold in a fair way.
HOWEVER, I did find out that there was an exploit to get around it (one of those rare exploits where you would WANT a bit of lag). Basically if you spammed “X” to sit/stand/sit/stand, then if a mob hit you while you were sitting and right as you were standing up, then it would register as a crit, but on the server side you would be standing, thus allowing the ability to proc.