Warlocks have received new spell effects; all the other classes received new effects in Legion. Male orcs are now able to toggle between the initial hunched posture and standing upright by using a barbershop, but the other races are not able to toggle between two postures. There are new druid forms for the allied races, i.e. a Zandalari troll forms are all dinosaur-based, while the Kul Tiran humans take forms made of wood and bone as their teachings come from the Drust people who populated the land before them rather than the Cenarion Circle.
Mag'har orc - "For untold generations, the orc clans of Draenor battled one another in endless war. But when Gul'dan offered them the blood of his demonic masters, the disparate tribes of Mag'har—the orcish word for "uncorrupted"—refused the dark bargain and banded together to drive out the Burning Legion. United under the leadership of Grommash Hellscream, the Mag'har pledged to one day repay Azeroth's heroes for aiding their cause. As war against the Alliance intensifies, the Horde must call upon the might of the Mag'har to seize victory."
Warfronts are larger, 20-man challenges that take inspiration from the Warcraft strategy games. Players are deployed on the Warfront to collect resources, destroy enemy troops, construct buildings, and eventually launch an assault to take over the enemy base. These battles take 20 to 40 minutes to complete and, unlike Island Expeditions, don’t offer a PvP mode.
Yes. I believe so. It plays nice with most Addons; even many that are out-dated. The only Addon with known issues is the mini-map in Bandit's UI (the rest of Addon works well with this Addon). The issues with Bandit's mini-map are fixable by disabling its mini-map (how to do that https://i.imgur.com/2zl3IEV.jpg) and using Fyrakin's Minimap. I found no issues with Fyrakin's Minimap. I have not testing other mini-map Addons but I assume the results should be like Fyrakin's.
As for the classes themselves, they almost all play like slower and slightly less interesting versions of their Legion counterparts. This is thanks in large part to the loss of one ability from each class that came along with Legion’s own AP dumping system: the artifact weapon, which added a unique ability to every spec in the game. The loss of these abilities left most classes feeling frustrating and incomplete, and though Azerite gear was supposed to be the replacement, it missed the mark completely. There will always be one Azerite trait that reigns supreme for each spec, meaning that the frustration of that particular loop will be unavoidable as long as the system is in the game.
That lack of storytelling agency may soon change with Patch 8.1, Tides of Vengeance, which is coming to Battle for Azeroth soon. While there are plenty of fun gameplay changes that should make the expansion better, one of the most interesting additions is that of choice. In an upcoming quest, players will be able to choose whether they want to support Saurfang or Sylvanas — essentially honor or evil — in the struggle for Horde warchief.