Any tendency that has reached reflective equilibrium in your current state is about as close to a preference as you're going to get.

But if you know your destination, you're already there. In principle, there is no need to wait for a tendency to manifest, or even to require that the conditions making the tendency manifest ever hold, if you know the way it'd go (not that you should just step back and watch). There are also one-off decisions that require knowing what to do this one time, where the intuition about reflective equilibrium applies less, and it's harder to express the correctness criteria in terms of "tendency", maybe only as a tendency to use certain considerations in making decisions.

Thus, knowledge of preference both makes sense and might be required in the absence of a currently stable tendency, even if we start with a tendency-based idea of preference.