Role of ALU in executing MOV instruction
Depends on the ISA and implementation.
Your ALU may have a pass through op, or it may not. There are tricks like OR(0,X) to allow it to pass through if it does not.
Or there may be a bypass path around the ALU. In that case the ALU may have a different role such as calculating an address for the MOV.
Without knowing which CPU you are talking about this question cannot be answered.