Your answers to questions about your intent may depend on the order the questions are asked. Or they may depend on what knowledge you have, and if you study different things you may come up with different answers.

If I ask the genie for long life, and the genie is forced to decide between a 200 year lifespan with a 20% chance of a painful death and a 201 year lifespan with a 21% chance of a painful death, it is possible that the genie might not get my preferences exactly correct, or that my preferences between those two results may depend on how I am asked or how I am feeling at the time.

But if the genie messed up and picked the one that didn't really match my preferences, I would only be slightly displeased. I observe that this goes together: in cases where it would be genuinely hard or impossible for the genie to figure out what I prefer, the fact that the genie might not get my preferences correct only bothers me a little. In cases where extrapolating my preferences is much easier, the genie getting them wrong would matter to me a lot more (I would really not like a genie that grants my wish for long life by turning me into a fungal colony). So just because the genie can't know the answer to every question about my extrapolated preferences doesn't mean that the genie can't know it to a sufficient degree that I would consider the genie good to ask for wishes.