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.”
Kaivax, a WoW forum community manager, revealed that WoW Classic's class design, battleground mechanics and stats on existing items will be set to their 1.12 state, despite the game releasing content that expands beyond that. This removes "progressive itemization," so if the stats on a specific piece of equipment was changed during the original updates, that won't take effect in this version.
2. Achieving. There are many pet battling achievements in game, and following the natural trail through the Taming [Continent] achievements up to Pandaria, and then on to the Spirit Tamers, Beasts of Fable and the Celestial Tournament was an epic journey for me and for many others. It's well worth doing. The Celestial Tournament is still, IMO, the pinnacle of PvE pet battling. However, WoD and Legion and BfA have added more battling achievements.