We have to travel to the past, in the times of the second war, because the bronze dragon flight have discovered that an old god is trying to change things in the history of azeroth by empowering the infinity dragonflight, and you have to travel to the past
That would be like exploring the easter kingdom as they were in WC2, before the scourge invassion, and with the old horde dominating the south part of the continent.
Some races like night elves, taurens and pandareans would receive a "magical disguise" so they can support their respective factions, I mean, that will not visually by the players , but the NPCs would see a night elf player as a "high elf" or a tauren as an "Ogre" (this will be only for questing dialogs, there is not going to be a visual thing for the gamers, like in the "culling of stratholme" dungeon )
In my opinion, this is not going to be like "revamping" old content, it will be like exploring a total new continent, yet something familiar.
There will be things that you do in the past and can affect things in the current time ,like planting a seed in the past, and return to the present to receive the fruits.
Something like the gameplay of Zelda Ocarina of Time
In fact the ruins of Stormwing would serve as a Raid instance.
What do you think?
**Please fix my grammar, english is not my language