All 330 crews are MFF, the recruitment is for an overall increase in fleet size.
Senior FO's from the 330 who are getting their commands this year are being replaced by more junior FO's who will have to commit to 2 years MFF before being eligible for command training on the 320/1. This is causing a few problems for some of them, but it's not such a bad problem to have to resolve in the present climate.
Make of this news what you will :-)