That makes some sense, the Elf subtype not making you an actual Elf that is; you might be distantly related to an Elf, or through magical means, become Elf-like, just as you would a like an Outsider, albeit you are not actually an Outsider. For example, a Human Monk becoming an Outsider through Perfect Self is still a human being despite gaining Outsider qualities through magic.
Anything with a "humanoid form" should be a Humanoid Type or Monstrous Humanoid Type. For example, a Zombie Human Commoner is still a Humanoid despite having the Undead Type (and Zombie Template), so it still is humanoid. However the inverse should be true? I don't have the book at hand, but Anthropomorphic Animals from Savage Species should be a good example; they're animals that gain the Humanoid Type if I recall. I may be wrong, however.