Assuming that the instructions say "no GFCI," we most certainly have a conflict within the NEC.
It is not an NEC or UL conflict.
The conflict is with the selection of incorrect equipment to use in a commercial kitchen regardless if it is listed as a 'Commercial refrigerator' if the manufacturer requires 'no GFCI' it is the wrong unit for a commercial kitchen....assuming it's 15 or 20 amp 125 volt cord and plug connected.
Whoever picks the equipment for a commercial kitchen must pick equipment that will allow compliance with any and all codes.
