I don't know if they are up to code or not, we had some reservation as well, and when we had the building inspected we had the fermenters out in ambient and never mentioned the freezers.
There are no laws or codes that specifies that beer has to ferment within a specified temperature range or at least none I have ever seen. Too warm and the yeast die and too cold they hibernate. So, beer can be legally brewed at ambient temps or controlled to be fermented cooler or warmer, Brew-master's choice.
If not, then you couldn't have steam beer which are lagers fermented at ale temps or ales that are crash cooled.
You could use swamp coolers if you wanted to. The inspectors are concerned with consumer (and employee) safety, not the intricate tweaks of your product. Ambient fermented beer doesn't present a hazard, just bad product if not in the proper range.
Processing meat or produce is different because improper storage, cooking or handling temperature becomes a consumer safety issue.
And the coolers you are using doesn't endanger the finished product, like its actually coming in contact with the beer, its just controlling the environment around it.
This is science as Tubercle understands it.