In that case is it not possible that BR might still try to frustrate CI by applying for extra flights to CDG (If France offers more slots) and make it double daily with the B787-9 (I think they are getting some).

With the reduced passenger number per flight and more frequency they could do it and keep profitable.

I think unlikely but surely a good 20-40% of their passenger loads will choose CI if they offer a flight to CDG as well. That would then make CDG unprofitable for BR as they have no alliance partner at the other end.