...they obviously read the many posts and acted upon them...
Yes and no. I mean, yeah, we got an expansion focusing on vampires, but not really in a way a lot of us who were vocal about our displeasure with the vampires in Skyrim wanted.
Personally, I wanted Volkihar that could do all the stuff I read about in Immortal Blood. I wanted the Order to be inching its way into Skyrim. I wanted the new Vampire Lords to be a different strain altogether, threatening both strains.
Instead, I got a complete mess in regards to vampire mechanics that try as I might does not make any sense at all.
To answer the OP, I don't want the Vampires and Lycanthropes to be the focus of new TES games, but I do want them to have more to offer as characters than featuring in one questline or being found in the odd dungeon here or there. They should be more properly integrated with the world. They should feel dynamic, diverse, and alive. They should offer new gameplay options, because of both the bonuses and penalties that come from being one.
In short, I don't want them to be treated as just different monsters for you to fight, but as different races and characters with their own cultures, systems, and social structure.
Imagine a game that allows you to traverse and explore this world, until one day you are infected with one of these multiple diseases and you turn. Suddenly, the world is completely different, and you discover there are numerous societies that were completely invisible to you when you were "normal."
If you want to know more about my thoughts on this, I suggest clicking the link in my signature.