*IF* some variation of the timeline centric expansion is true. Then what that tells me is that Blizzard wants to go back to "Warcraft", in terms of what the general gaming populace knows of it, aka ex WoW players, people who dabbled in the RTS games etc. Which is pretty much Warcraft 3 + Frozen Throne + Classic WoW + BC + WotLK. Most people are not familiar with the War2 story and characters, and most people are not familiar with any story bits in Cataclysm or Mists of Pandaria.
In terms of lore, this kind of story would not really advance the overarching plot of WoW as of today MoP edition, but the idea is to just bring the look and feel of the world back to what most people are familiar with.
From a marketing perspective, the ability to tell people that "Warcraft is back!" and then show a bunch of classic Warcraft imagery and characters is probably too temping for a company that has been bleeding subs for years now. Its either that or introduce a new continent/zone, where some great evil has awoken etc.
If the choice is nostalgia pandering and revisiting Draenor with characters we know off and races and villians we are familiar with vs. doing another MoP, this time with...pick any race you want, Murlocks, Naga, whatever that is neutral race and their continent/zone is under attack by this great evil. Then i know which one i prefer, but i understand the people who wanted the story to go forward instead of looking backwards. But if they have no great ideas or concepts for where to take the story next, then its perhaps best to go backwards to the tried and true. Its not just a coincidence that Heartstone features the original 9 WoW classes, its what most people familiar with the franchise identify with most.
TLDR: If this is true, then they want current WoW to "look" like the type of WoW most people are familiar with, if that means Back to the Futuring the game, then so be it.
