I'd enjoy the game less, because it wouldn't stay true to itself. Here's an example. You play WoW as a Human Paladin. You read/played just about everyhting in the Warcraft universe, and then they release Wrath Of The Lich King, with the Nightelf Death Knight...in theory, you should be like "WTF, Nightelves can't be Death Knight, they're protected from the scourge !". After that, you have Cataclysm with the Nightelf Mage..."That's bullshit, Nightelves can't be mages ! The Elves mages are the High elves, thus the Blood Elves !"...in all that, you still play a Human Paladin, so it doesn't change the game for your character. You wouldn't be (haven't been if you played WoW) bothered by that ?
Or else, if they decide "Fuck the lore, let's bring this character back from the dead without any explanation !" wouldn't it bother you ?