The first time I took off on 09R at Heathrow we were warned we'd be making an extremely sharp right turn immediately after take-off for noise abatement reasons. That duly happened - but they don't do it now. Why not? (It was a MAS 747).
Not related to Heathrow but some years ago I was on a United 777 from San Francisco to London. UA have the ability to pipe the ATC into channel 9 on the IFE and I was listening as we taxied out. As we approached the runway the controller asked "can you accept a shorline 9 departure" to which the answer was an immediate "yes" followed by ATC asking "are you sure". There was then a delay before our pilots once again said they could accept the departure. We lifted off and immediately turned right; the normal long haul departure from 28R back to London being straight over the peninsular to the ocean and then a right turn.
The point is that just because you haven't experienced the same departure as the MAS one since it happened doesn't mean it never happens.