If they do say No, it eventually leads to the pixelmon server response just like Yes does. There is no difference except the immersion into the mod, which WILL let them catch pokemon, there is no harm in that.
Also, "If they can't handle the truth, they don't deserve to be on the server" implies that you give no shits about how many players we actually have, and don't care at all about other people in general. You don't want to give them a chance to stay, a chance to stay with the community on the pixelmon server, you just care about people who blindly have faith that pvp is a decent alternative, and I can't condone that. By the way, WHICH SERVER? That quote was made how long ago? We have more than one server now, so I think that quote is broken.