While I would agree with you I highly doubt that I would have been the only one with the problem then, and I would still exist in some way to be added to the group. When this problem happens the game states that "This player is offline or doesn't exist.", both when I add to my group and they add me to theirs. I also haven't done dailies on Iokath in a few days prior to this. It is very highly likely that alignment has no effect on this situation. Also considering I could get into the Gods from the Machine on a character that couldn't even choose sides, and the unaligned location of this operation, both let me conclude that, once again, it has no bearing on this.