Hello. I am not an expert. But I went to read the species description from the 1800something paper. There is nothing to suggest it has a penis or some kind of reproductive organ of remarkable length. Instead, it does seem to have very long wings, and since cockroach forewings have a pennate structure, it stands to reason to think that the perpendicular venations in the wing are long, because of a combination of angle and length available. Therefore longipennis.

Now this is just guessing, so of there is someone who knows better I'd love to hear about it.