Well, I don't know how things work in your area, but here if I get contacted by a DM asking me if I would be interested to join his group, then that's typically the only person I'm in contact with until I actually join the group for a gaming session. I'll either create my character on my own based on the information I receive from the DM or I'll meet with the DM to create the character under his direct guidance. Alternatively, I've sometimes been asking the DM if he has a pre-gen I might use, particularly if I'm new to the system or setting. I don't think I've ever contacted any of the players in such a case or was introduced to them before meeting for the first session (unless it was one of the players who introduced me to the DM in the first place).My point here is that actually examining whether your assumptions and preconceptions match the rest of the group's play-style and intent is part of your responsibility as a player. "The GM didn't explicitly tell me," is not an excuse.
So, I have to make certain assumptions, e.g. that the DM actually asked his players if it was okay that I'll join the group! And if the DM doesn't realize that my character might cause problems with the rest of the group I really don't see how the hell I should realize that before the first session?
Of course during the first session I'll typically hold back to get a feeling how the others are playing, but if I should notice that either the pcs are completely at odds or the play style isn't anything like what I've been told beforehand then I think it's the DM's fault, not mine.
What will happen then is that I'll either roll up a new pc that could actually work with the group or the first session will simply have been my last session with that group.
I'd like to note that I've rarely left a group because of one (or several) of the players (Well, there was this one guy...). It's usually when I dislike a DM's style that causes me to quit. And I don't recall having been kicked out of a group, either. So, despite my inexcusable assumptions and preconceptions and my disregard of my responsibilities as a player, I tend to get along well with (new) players, even if the pcs don't
