yes: i think it should be the hosts job to inform everybody involved in the game if its a big map or not, especially when you do not need to click the map to accept it in the game lobby, it should absolutely be the hosts obligation to make everyone clear before they light up.
no: i think it should not be the hosts job, if people want to trick you into playing a big map, they should have that right. its your fault for not being more aware, and asking if it was a big map before lighting.
there ya have it folks, by the request of Tomi, i will not post my educated guess on the percentage of games played with normal maps

please vote.