Don't think there is much happening that's out of the ordinary. I would have expected BA to send up a couple of heavies had it not been for Virgins intrusion on the route so just a couple more A321's at best.
KL have got an extra 737 on Friday, LH the usual 735's, some AF 190's but really bugger all difference from any normal week.
Last proper widebody was in 2010 with a BY 767 to the Caribbean IIRC via BFS. Unless a C17 is counted which pop up every now and again. Pre-dates my interest in aviation but I don't think BA have had a 767 on the LHR run for 10 years at least.