'If analog audio is AC, then doesn't that also defeat the purpose of direcional arrows on interconnects as well as speaker cables?'
In a nutshell, yes! BUT, the arrows (if these exist) could indicate where the shield is connected, usually at the preamp, but should always be a common place. Therefore, in a typical setup, the arrows on the cables from a turntable would point towards the pre-amp and the arrows for the cable to the power amp would point to the preamp also, which would be counter intuitive to the myth of current direction, i.e. to wards the power amp.
In a nutshell, yes! BUT, the arrows (if these exist) could indicate where the shield is connected, usually at the preamp, but should always be a common place. Therefore, in a typical setup, the arrows on the cables from a turntable would point towards the pre-amp and the arrows for the cable to the power amp would point to the preamp also, which would be counter intuitive to the myth of current direction, i.e. to wards the power amp.