It is slightly different to Waze, I believe Google Maps only shows the position of fixed location speed cameras and as such they can just not display them for certain countries where it is illegal to do so. Waze is crown sourced with cameras added by the public right down to real time mobile speed cameras.
They could of course also not display these in some countries and not show the ability to report certain types of events like police locations or speed cameras.
Over time the features of Waze and Google Maps will converge. Whether they will eventually become one, who knows. Not for a while I don't think, Waze will be the community sourced option and Maps will be a read only presentation of that data.