The article posits that they may just have centralized monitoring, not control. Since this didn't affect every location, I would assume it was a shared default password or something

This _IS_ the U.S. Government.

Because they’re prefabbed walk-in coolers or freezers (at minimum, they could be purpose built cold storage warehouses) with multiple condensers, evaporators, pumps, temperature sensors, and humidity sensors. The refrigeration equipment needs some sort of control system and direct digital control is the usual way to do that these days.

This is food storage for a commissary, aka a store. They don’t use residential refrigerators.