I wonder if some of this relates not to our potential mechanical, physical hearing differences but more our more likely than not similar acoustic environments we experience growing up.Your idea makes no sense at all. If a person has elevated 14 khz, they hear that as normal. If you do away with or diminish what they normally hear they aren't going to hear what is normal to them. It will sound altered.
As to what someone prefer's, all bets are off. People prefer many things for many reasons beyond fidelity. You cannot know that someone with elevated 14 khz response prefers it be rolled off. They might, they might not, but we can say what they hear won't be high fidelity.
If we took ten people from a pre industrial environment, say the rain forest and tested them.. then again how much of our hearing is based on past evolutionary events and comes pre programmed in our genes. This being so maybe we would have more in common with a pre industrial people's than we would assume.
Who knows .