Disney presentation at Upfront.

[Kane's other son]

The marketing that we do have, including that little cast interview, seems to be going all in on the "five species" thing, so it seems that the four other lowercase-a aliens are going to be pretty prominently featured.

Five species, five Engineer "temples" on LV-223. Wouldn't that be cool?

[skhellter]

five variants of the "Alien" itself, maybe.

the Alien Engineers script did have multiple areas within the Juggernauts, each with their own type of Alien Eggs.