See, I don't buy that?
1) How is it hard to implement the Volkihar. Tunnelers of New Vegas burst from the ground, Spriggans IN SKYRIM come out of "the walls" (trees to be more specific). There's no reason Volkihar can't use these scripts.
They were probably by set points, which is why you dont see much of them around, they perhaps wanted the Vampires to be a more "common" enemy so people had a good chance of contracting the disease, yes i was dissapointed when the Volkihar were no more than normal vampires after i had spent time to find one and then let it disease me up just for it to be the same disease as every other vampire gives you, they had had a choice of a few but well animated volkihar -which may of been the right choice- which would of then annoyed players when they then couldn't do the same things.
2) A certain faction in Skyrim are werewolves. Instead of werewolves? Make them werebears. PROBLEM SOLVED. Yes it'd be nice to have both, but if there's truly time restraints, I think werebears, according to established lore, imply the werebears take precendence over werewolves. And hell, what are werebears? A re-skin of werewolves. That's literally all they are. Not that hard to implement....
I think this was a choice between fans demands and lore , its true it may not of been too hard to implement both although it would then lead to problems between who gets most attention. But in the choice between Wolves/Bears there was more a demand for Wolves as they had been showcased before in Bloodmoon then dissapeared.
Sort of off-topic, but if we went to Elsweyr in TES VI and the Aldmeri Dominion governed them? I would actually be ok with this. Why? Because Skyrim provides reason to believe such an occurance is plausible. Smooth, natural transition. That's what this change in the Volkihar lacks. One moment they're popping out of lakes, the next moment they're pimpin' it up in castles and watching Underworld movies all day.
Which is a cheap excuse and a poor writing technique. If you're just gonna say "THE NEXT ELDER SCROLLS WILL TAKE PLACE 8923895928357 YEARS IN THE FUTURE" to alleviate yourself of any responsibility to your own lore? Then don't bother with lore. Either commit or don't commit, but don't half-ass it.
I still reject the idea that this is heavily stolen from movies -such as underworld- Vampires are usually being depicted as having some sort of powerful coven and usually in some sort of big dark castle and think they are lords, Underworld probably wasn't even the first to use this Flying Vampire Lord description, it is simply a modern version of it which was well received and therefore what people associate with the image. I see no problem with Bethesda saying we got an idea for our game and here is a movie that has done a good job at depicting something similar to what we are talking about shall we take inspiration from this...