If two fleet is the way to go, then there can be no more 320's. All will have to be wide-bodies (787 & 777 or 350 & 340 as mentioned above). Assuming the 350 and 787 will have similar (or close) operating costs, the 777 might have an advantage over the 340 esp when yoiu compare operating a 2-engine aircraft vs a 4 engine one. Last year was a record setting year for the 777 and a very bad one for the A340.
As far as I know, none of the owner states gave discounted fuel prices to GF (even AUH which is overflowing with oil), which means the loses this year could hit a record (unless the owner states help out).