Orpheus does not kill the party or at the very least there are the two options, so far I cant replicate the outcome of orpheus killing the party
Moreover, the page seems to be very biased, it's just a game, and we shouldn't write about these characters or what they do judging or assuming intentions, Let me provide a clear example, it says that -not revealing that he is Balduran- is "treachery" but it is not, he doesn't benefit from not saying it, he is not betraying the trust of the protagonist by default, while it is interesting it is not supposed to be relevant to the main gameplay, it doesn't affect it, also the emperor seems to have the goal of defeating the absolute and or saving baldurs gate most of the time, which TENDS to be in line with the goal of the protagonist, so its very easy to argue that he never withholds information with bad intentions.