dnd 5e – Familiar chain-puff creature type

The well-known saying states that the familiar is a celestial body, an enemy, or a fiend (instead of the beast).

In my understanding, all Familiar's summoned by Find Familiar are only ghosts in the shape of the selected creature (and not a true example of the creature itself).

But since the spell indicates "instead of an animal," the confidants of the Warlock chain pact (Imp, Quasit, Pseudodragon, and Sprite – neither of which animal) will change the creature type to the mind that has taken its form?