rules on exile?

so... I have seen one banishment on the board (Easthollow).

but I was wondering what are the rules on banishment? Since it is a large change, do you have to seek OOC permission from the player, since it has the potential to uproot their typical plots?
what if the player says no, but it no longer makes sense that the leader would harbor that individual?
and does it make any difference whether the pack leans towards democracy or totalitarianism? 

thanks in advance!