Uso, keep in mind that the article states that the FOAM reacts at temperatures of above 100 degrees Celcius, which means that the reaction would start before the FOAM would come in contact. It would still throw flaming materials, but since in comparison to the fire, the force of the reaction would be pushing away from the person with the extinguisher. So it will still throw materials, like you said, but only within about a 100 degree angle.
So it would be effective for fires that are in corners, more enclosed space, etc. But that's just my take on it, I may be wrong.