I would expect controlling of propellant flow into a combustion chamber has many lessons that can be applied to other fluid dynamics problems. And it says right

I would expect controlling of propellant flow into a combustion chamber has many lessons that can be applied to other fluid dynamics problems. And it says right there that is what they did: "HMA incorporated elements derived from ORBITEC’s propulsion work into its design for fire suppression." Sure it probably isn't the vortex itself by the sounds of it but there are plenty of other problems they would have had to solve to get the working engine design. So there is no stretch as I read it, though I appreciate your skepticism as often these things are blown out of proportion by the media.