>>41358500I imagine most of the "gender unknown, but capable of breeding with Ditto" have some form of non-sexual reproduction. Polteageist is canonically capable of asexually multiplying, Cryogonal is born from clouds, Minior is born from atmospheric debris, Shedinja arise from Nincada exoskeletons, and most of the rest seem to have artificial origins.* Maybe Falinks are literally inky creatures that divide themselves to multiply.
*Staryu and Starmie are interesting. Aside from Nihilego, they are the only gender unknown Pokemon based on a real life asexual animal, however based on them having egg moves coded in GS, they were likely intended to have gender at some point. Cryogonal, Minior, and Dhelmise being able to learn Attract may point to a similar story. This makes me think that "gender unknown but able to breed with Ditto" is SUPPOSED to be exclusive to artificial-looking Pokemon (Voltorb, Magnemite, Porygon, Baltoy, Beldum, Bronzor, Rotom, Klink, Golett) but sometimes they fuck up.