Depends on the extinguishing media.
Halon is a low-specific-heat gas that does not result in shock cooling of the hot engine cases, and is thus fairly benign to an engine's integrity.
Other gases - perhaps more environmentally friendly - have higher specific heat values, and the shock cooling they cause is not good to compressor/turbine cases, which after all are highly loaded pressure vessels.
So the choice of extinguishant is a tug-of-war between the engineering camp and the greenies.