Avionics is the area that is the least tolerant of radical redesigns in human interfaces. This FMC form factor has been around a long time. There are newer ACARS/FMC systems that have an actual QWERTY keyboard.
Use bépo, of course! More seriously, Airbus uses qwerty since at least the A380. This means that the A350 and the A330, two aircrafts that share a type rating, do not use the same layout.