To assume that the AF crew was operating this flight, transatlantic and during night, with the WX radar turned of or without monitoring any WX radar returns is an insult for the crew, an insult for all of us professional pilots!
These pilots where professionals, trained for 100s of hours with a vast experience.
So NO, the WX radar off theory does not FLY!
What happened here is a domino effect of events, leading to a disaster! You can be sure of that!