I don't know about Airbus, but on Boeing aircraft there is linkage as part of the throttle lever that:
a) prevents movement of the reverse lever if the forward lever isn't at idle, and
b) prevents movement of the forward lever from idle if the reverse lever isn't at idle.
It's all independent of the engine type - for example the throttle levers are common for all 747-400s/-8 regardless of the engine type.
It would take a physical breakage of that linkage to allow movement of one lever without the corresponding lever at idle.