Allow interested players request certain settings. Players could up-vote it, with narrators seeing that there is interest in certain settings. Setting can be selected from a list or chosen as 'custom' to simply describe the setting (dark gritty sci-fi or Romantic Comedy) as opposed to choosing one of the tropes.

A narrator could create a game and have it notify everyone that up voted that request, thus any people requesting that play-style would be notified when it came available.