Interesting- I always thought the cyberpunk future of self-policed corporate-states would be here eventually, but I didn't think firefighters would be privatized in that manner before police.
Everyone thinks private police and firefighters are some kind of abomination, but I say that there is no perfect solution. I don't think massively expensive public services are cost effective although they do serve the public at large without discrimination (some members of the public are much more frequent fliers than others, of course). Private ambulance services now abound and are quite successful at controlling costs (because they don't pay the EMTs who staff them very well).
We need policing of some kind, we need fire and ambulance coverage of some kind. It should not be illegal to hire mercenary detectives or firefighters, it's a supposedly free country. What we don't want happening is deep pockets hiring police to enforce their own "laws" as took place in the 19th century with the notorious Pinkertons, who were little more than thugs that would come in and break up protests or unionization attempts. It was all very dirty business.
The firefighters in NYC were basically little more than gangs for most of their existence. A fire would break out, the firefighters would come and fight over who was going to put it out, and meanwhile they would immediately condemn the structure so that anything of value inside could be pilfered. That history is why we have better control over our public services in the first place--cops and firefighters were just thugs with their own agendas for most of US history. These days they don't outright rob regular people, but they certainly do act as enforcers or "King's Men" in most jurisdictions and are not fully accountable to the public. Somehow firefighters are more beknighted, but behind the scenes, there is much dirt there, too. Dirty politics, nepotism, poor ethics.