Owenc,
I don't know why you would say the route will be pulled, it just celebrated a major anniversary and has been performing consistently.
I heard the comment about the 767 from 2 sources, 1 that works in at Heathrow and the same was in airliner world magazine. The article was about UA withdrawing from JFK and doing some slot exchanges with DL between JFK and EWR. UA ops were small at JFK anyway. But it went on to say 757s would be taken off TA and 767s put in their place.