A340x
I don't think so.
You think that, if they will get a lot aircrafts, they will need some F/O's on those planes.. True.. but they also need S/O's on those aircrafts.. so waiting time can exceed.. You got that?
If there will really be a shortage on the F/O seats, and the only option is to upgrade the S/O's, they will give the opportunity to the DESO's. They are 'just' for 18 months S/O and they have real flight time.
Don't forget this: a lot of aircrafts will leave the fleet.