Im with Topbunk on this. My airline has a policy of always keeping the Park brake set when parked. I have never known this to cause any problems with the brakes since it was introduced many years ago.
An Asian airline I work for always releases the park brake on arrival as soon as I have called up on the headset that the chocks are in. This causes us to rush out and place the chocks, so we can get the brake off before the jetty is in place, because on the very slight slope, the B777 moves a few inches as it compresses the chocks.