The token will still have any card types it normally has, such as creature or artifact, but it will lose any non-Alien subtypes it has, such as Human or Vehicle
For example, if the top two cards of your library are Brainstorm and the modal double-faced card Valki, God of Lies // Tibalt, Cosmic Imposter, you will end up with a modal double-faced card that has Brainstorm as one of its faces, and either Valki, God of Lies or Tibalt, Cosmic Imposter as the other face, with either face as the front (your choice)
Well also need to budget in the small but still meaningful mana cost when building our gameplan
Ive also found that the two Map tokens rarely come back to bite you
There's a lot of potential here for decks that like to self mill since you get a refund for the one generic mana you're paying, but the fact remains that you still need to pay the 2 mana up front