Sounds reasonable to me, though we need to have more details as to what the social contract entails.
I agree Rule Zero should be prominently brought back into the game. But playing a game shouldn't require a legal contract. "Social Contracts" are the anti-thesis of fun IMHO.
It looks like a request for the players to understand that the DM probably can't create the pen & paper equivalent of Oblivion, and not to expect this of him/her.
It's an agreement, often tacit, of the particular appropriate behaviors in a given circumstance. Thus, not peeing in the potted plants, not grabbing the host's wife's ***, and not backstabbing the rest of the party are all parts of a social contract. There are different social contracts for different social groups. Some behaviors only apply to some groups (It's O.K. to pee in the plants while camping, grab someone else's wife's *** during a swingers party, and backstab PCs in the right type of campaign). Social contracts are rarely outright discussed, but rather inferred from behavior and reaction. This is the source of many social errors either from entering a social group with conventions different from your own, or from disparities in agreement between what a social contract covers.