fly-by-wire is the flight control on the airbus which means that you cannot stall the aircraft by pulling the flight stick back too far etc. It essentially means tht instead of straightforward mechanical/hydraulic linkages from the flight controls to the elevators etc, there are electrical (i.e. wire) linkages so that the flight computer can stop the pilot from flying outside the aircraft's limits.
I take your point on flight dynamics - I agree and wish I had been asked only on those universal laws of flight but the point is I wasn't. I was asked about existing aircraft and their characteristics. Fly-by-wire is on all airbuses (and 777s) and is here to stay so I would class it as basic knowledge. My knowledge of it isn't great but they just seem to want you to have a general idea.
You may also want to consider that some aircraft have been around for 40+ years (747) and so the aircraft being produced at the moment may not actually change that much within your career. Also, whether the aircraft change or not, you will be flying the planes we have today to begin with.
I was also asked whether certain aircraft were wide-bodied or not and things like that.
