Many of these smaller stores (and probably some of the larger ones too) rent or lease refrigeration equipment from one of a handful big providers. These are large and expensive systems, and there is costly paperwork involved together with logistics suppliers to show that the cold chain is satisfactory.

These refrigeration providers work with local contractors and HVAC companies to set things up. Their installation techs do what they think is required to remotely operate these systems. If you bring up the question keeping these systems offline or at least on airgapped networks you will most likely get a shrug as reply.

This is not a technology problem. This is problem of responsibility. One can hope things will improve when litigation starts happening, but it doesn't look good considering these people had literally months of notice since the well-publicized attacks on the American fridges, then the French fridges, and now these.