Well, this is unexpected...
It probably is a test of Western interest. Not the best way to do it, but not the worst.
Off the screenshots linked in that article, we can guess eight of the twelve: Agumon, Gabumon, Biyomon, Tentomon, Gatomon, Veemon, Shoutmon, and Dorulumon. Yes, that is a bit Adventure heavy, but consider the alternative. If the parameter was "two per series", history suggests it would have been Agumon, Veemon, Guilmon, Agnimon, the other Agumon, Shoutmon, Gabumon, Wolfmon, Gaomon, Dorulumon, either Renamon or Terriermon depending on who made the decision, and I have no clue who the twelfth would be. While "neither" would be better, given the choice of "mostly Adventure" or "mostly dragons and dogs", the former is a less-severe mistake.
Though I do hope Terriermon is among the unrevealed characters. There's no good reason not to include him.