b) if there are test errors, then we should have a ticket. I don't see what kind of errors this change would fix

a) calling super with self as the instance is the "right" thing to do. If there are any state variable in the instance, then this is the only correct thing to do (see rvs). If we add a state variable in future, then this will break and we have another case of problems with  "hidden states because distributions are instances", in case the state gets changed by something or by the user.