{{citation-needed}}
Sounds like misinterpreted marketing FUD.
Also, correct me if I'm wrong but fundamentally HEPA is about removing tiny particles whereas other approaches catch larger particles, and organic fires mostly release larger particles. HEPA filters for your house are extreme overkill, it's like living in a medical lab.
"Activated carbon filters will remove chemical gasses. They work by adsorption, a process by which the toxic gasses are attracted to and stick to the carbon But there are problems with carbon filters. Since activated carbon simply collects toxic gasses and stores them, when the carbon becomes full of gasses, the gasses can release back into the air."
That is what I was referring to in terms of carbon not being a cure-all.
The first thing to note is that furnace filters are not HEPA filters. The second thing to note is that HEPA filters don't filter out the same things as activated charcoal (from what I understand).