Honestly, in a game of this epic scope and depth in a fantasy setting, I highly expect and want to see Elves and Orcs and Dwarves and Giants and everything else that's the usual "cannon" for most things of High Fantasy.
That's the road to stagnation. Like developers trying to create the next WoW.
Sounds like (just perception, sorry for it) "I dont want to care about what they are trying to offer me. I just want my standard and used to death stuff for fantasy." instead of "Let's see what new things can they add to the fantasy world.".
The "History of the Runestaff" is one of my all the time favourites and only features humans. But you get the so wonderfull "Beast Legions" (not sure of the exact name right now, sorry) in it, with legions of soldiers devoted each one to an animal and behaving in their tactics and duties like the animal of the legion. "The Ladies of Mandrigyn" is also a very nice fantasy book that features just humans (ok, undead and other creatures here and there but their are collateral effects ). And the Darwath Trilogy features just humans (vs the Dark Creatures, bringers of death and destruction, that incidentally eat humans) and I found it awesome and my favourites of all the books I have ever read (maybe tied with one trilogy from Louise Cooper, not sure of the title in english but if you have read it, the protagonist is named Tarod).
Not that I didn't like LotR (prefer the Silmarillion) or Dragonlance or Forgotten Relams... But nothing of all that will be above the simple fact of: give a solid, coherent and interesting world to play in/with/at.
Also, it's like obvious that Stardock will relase non-humans as non canon stuff? It's clear that people wants extra stuff (be it elves, dwarves, asian/greek based stuff like buildings/weapons/clothes,...), including expansive expansions a la Gal Civ II (wow, I would never dare to play the vanilla Gal Civ II again...). So no need to worry about the "no elves" in campaign and also, bad attitud to say that it's a bad decission not to have "elves and stuff" for the game anbd only have humans. It has been a while since I lose any interest in a MoM2. (even if my mod will use elves, dwarves and the like... but that's because of the original idea from which it was generated )