While it hurts Boeing to have these A343's sitting around, it hurts more to lose sales of new Boeing metal.
Long term, Boeing is a cheaper ride, and most folks know that. Two engines less to maintain, and the whole nine yards.
Right now, production planners at Airbus are looking at their run and it is not so pretty - which is why I say the A340-600's will be a hot property to land on someone's doorstep. The pricing is excellent, and given the Canadian market, they are a safe place to put them looking forward.