I asked a forester. Admittedly this is not the best response for a pseudonymous internet forum.
Further searching for links on serotinous (externally triggered) cones turn up sources that almost all refer to the Lodgepole Pine [0]. Also note that these trees have both serotinous and non-serotinous cones - they can still reproduce without the presence of fire, albeit at a lesser rate.
That being said, the Ponderosa is fire-resistant, and will survive typical non-crowning fires.
Further searching for links on serotinous (externally triggered) cones turn up sources that almost all refer to the Lodgepole Pine [0]. Also note that these trees have both serotinous and non-serotinous cones - they can still reproduce without the presence of fire, albeit at a lesser rate.
That being said, the Ponderosa is fire-resistant, and will survive typical non-crowning fires.
[0] https://www.fs.fed.us/database/feis/plants/tree/pinconl/all....