#2 - Dec. 13, 2017, 6:03 p.m.
Wowhead has a good run-down of how to get into shape for 7.3 content, and I feel like they've a great job keeping folks informed on stuff like that. You can check out that guide
here, but if you're just looking for a quick rundown of what came with 7.3, you can check out the Shadows of Argus trailer
here.
The story is something you should experience yourself, so I'll leave that up to you! :)
Welcome home!