>>279928051They didn't even team up with the adults. The pilots never had to do something like reconcile with APE to fight a larger threat, because all of the 'real' adults got raptured offscreen with the aliens arrived. The 'adults' that were left were always just the disposible tools, barely older than the pilots themselves and similarly treated as trash by the greater society of immortal fucks.
Pilot revolution against APE, probably involving reaching out to and allying with the Klaxosaurs on the promise to stop using Magma energy (which the pilots, rejecting the immortality tech and the self-contained Plants cities, wouldn't need) was what the show was building up to. Aliens could have been hinted at as a twist, but never having more show up than the 3 specific founders of APE that kicked off all of this as a surprise final boss fight that only reveals itself AFTER the human threat has been dealt with. Maybe leave the door open to a sequel series or movie because the rest of the aliens are still out there and now they know that their espionage plan on Earth by subverting humanity to do their dirty work for them has collapsed. But certainly no more than that.