As mentioned, the MEL departures are not RWY specific and neither is the airways clearance, which may have something to do with the propensity for ATC to change runway configuration at the drop of a hat....
I think the explanation for runway changes have been covered ad nauseum in other threads however I’ll say it again here. ATC cannot nominate (or continue to use) a runway which has in excess of 20kt crosswind or 5kt tailwind - or any tailwind if the runway is not dry. These are not rules that we like but we are stuck with them until our customers pressure airservices or CASA to change them. CASA, the airlines, the insurance companies, and lawyers (and most of the experts on here) will have our arses if there is an incident where disregard of those rules could have possibly played a part.
I always specify the runway as part part of the clearance (runway 34 Keppa 1 departure) or say ‘information November, runway 34, cleared to....’ etc on clearance delivery but the vagaries of Melbourne weather, or TMA requesting LAHSO may mean that the runway will change before you push back. As an aside the ATIS may have been nominating a runway configuration for an hour or more and some pilots are still surprised that they’re not for 34 when given taxy instructions.