I guess it's an impression I got from reading many conversations here.

I would expect that most conversations involve currently endorsed preferences, simply because it's much easier to discuss what we should do now given what we currently think our values are, than to make any nontrivial progress towards figuring out what our values would be if we were fully informed. I don't think that constitutes evidence that people are forgetting the distinction (if that's what you meant by "going out of fashion").

I'd be interested to know if you had something else in mind.