Does your NOPs not say the following.
“Check that the ECAM E/WD displays that the reverse deployment is as expected (REV green)“
The words here is AS EXPECTED. On single engine, you are not expecting it to work ?
On a flight with one dispatched as INOP, you are not expecting it to work ?
I think the call of “NO REVERSE” is a prompt to let the PF know they have either forgotten or have not selected correctly.