Andrew
I'm not sure if the BA board has answered your question yet, but all ex-LHR 777s have NCW and not cradle seats.
There was a lively discussion about 4 months ago around the issue of BA withdrawing F service on some routes, and YUL was one of them. I think Philadelphia and San Diego also lost out. It seems like the reconfiguration has taken place. Have you tried calling BA to see what they say?