World of Warcraft hasn't changed almost at all since pre-BC in terms of gameplay.
With everybody's bullshit about how the game used to be hard, game used to be challenging, blad de fucking blah, all they mean is that loot was less accessible, and in consequence, characters stayed weaker for longer periods of time, creating an illusion of difficulty.
Whether loot was less accessible because it took longer to farm mats, farm reps, because quest rewards sucked dick, it doesn't matter.
In terms of actual gameplay, barely fucking anything has changed in this game. Scenarios are smaller dungeons, raids have a billion new "difficulties" (read: ilvl gear checks), at the end of the day, you kill dumb mobs to get shit from them to get better gear.
Wintergrasp was the first real gameplay improvement in WoW, improving it by offering a new way to think and to play the game. Through siege weapons and destructible environments, it created choice for where there was none before. It offered new challenges and new fun moments.
The new AI scenarios (and hopefully, new AI everywhere) introduced in BFA will introduce (fucking finally), AI which think and reacts to you, just like in games like Halo 1, Division, Destiny and others which have long ago surpassed WoW's static dumb mobs. It will be the only fresh of breath air since WOTLK for WoW's gameplay. It will make PVE combat fun, which is what a video game should strive to be first and foremost.
I cannot fucking wait to see this game's gameplay to move forward in actual challenging ways. It's what an MMO of WoW's status and reputation deserves, not to be slowly let to die with tired systems and clinging to old ideas which were never that great to begin with.