We can't exactly prove that I suppose

I'm just depending on the idea that closing the game also closes the current proposal but saves the fact that there was an incoming proposal..
then when you next open the game, the random generator kicks in to give you your next proposal. Only way we'd know for sure is to have one of the staff members let us in on its secrets

Edit: Actually, when we use backups the game will not remember us rejecting or accepting a proposal, and it'll show a new one anyway! That's how I came by my little theory.