Normally i would vote for more hardcore approach. Especially when it comes to roleplay.
However when it comes to writing, it's all comes down to specific writer point of view. And i can't even remember how many times in games i encounter situation when writer probably thought that most players will judge same as he/she. But in reality players was entirely confused, picked "wrong" dialogs, and went with choices they was not satisfied at all.
So it would be very nice to give small hints on dialog choice, on how every character in party will react to that.
Largely a metagaming yes. But it still would be nice to know for sure, rather than guessing (and again often guessing wrong). Plus for myself i know i still would pick from time to time options that possibly would "piss" my favorite characters.
