That is one explanation and the other, closer to the sponsored research, is that, like a candle, with heat applied the material gives of vapours which can burn. Remove the heat source and everything cools to being inert again.
The issue in the 787 case is to detremine what was the initial heat source. If it was the ELT itself then it would be a first. If it was something in that area which then caused the ELT to generate enough heat, maybe. But what if the heat source managed to bring e.g. CFRP material up to the temperature where it and/or other local materials gave off combustible gasses which then sustained the burning and then caused the disruption to the ELT?