"I value the kind of future that is well-liked by the people actually living in it..."

If what you value happens to be what's valued by future people, then future people are simultaneously stipulated to have the same values as you do. You don't need the disclaimers about "honest value drift", and there is actually no value drift.

If there is genuine value drift, then after long enough you won't like the same situations as the future people. If you postulate that you only care about the pattern of future people liking their situation, and not other properties of that situation, you are embracing a fake simplified preference, similarly to people who claim that they only value happiness or lack of suffering.