Drew, of course it’s a population report. The joke is that people call it a popularity report because more popular cards are submitted and therefore pop reports index the popularity of cards and not the actual rarity, as papafrankgod said. Nobody here believes that pop report is shorthand for popularity report.
The point that I was making is that no species is more likely to get printed than another one, as Pokemon set cards are printed on sheets and equally distributed. When there are differences, as seen in the 1st ed Charizard and Clefairy pops, it’s due to popularity, not because one is printed more than the other.
Regarding Korean unlimited, yes these are rare and niche cards. At the moment, I don’t think much can be gleaned from the pop report beyond that very few have been graded in total.
This conversation reminds me of this thread, and how very niche cards can sometime present themselves as very rare cards. In this case, Korean Unlimited is both very niche and very rare, but the effect on the pop report is identical (i.e., low pops).