Warning: this article contains spoilers for Ant-Man and The Wasp! Read ahead at your own risk!
Some significant changes have occurred in the Marvel Cinematic Universe over the course of the last few months. Even for a small-scale adventure like Ant-Man and The Wasp, we now know far more about the Quantum Realm than the first film ever let on. With that in mind, it looks like there's even more down there than we ever thought possible, as producer Stephen Broussard recently opened up and admitted that a possible third Ant-Man movie could continue exploring that complex sci-fi landscape based on the elements introduced and expanded upon in the second film. Broussard said:
So, while there is currently no guarantee that Ant-Man 3 (or Ant-Man and The Wasp 2) will actually happen, there seems to be a basic roadmap in place if Stephen Broussard, Peyton Reed, and the film's team decide to head back in for another. For now, we do know that the continued exploration of the Quantum Realm could play a role in future installments, with a more in-depth examination of Janet's time trapped there helping to inform the direction of the story. There are apparently bits of possible foreshadowing for this, based on what Stephen Broussard said during his appearance on The Empire Film Podcast, and there's an implication that the Quantum Realm contains more waiting to be discovered, especially where Janet van Dyne is concerned.
That specific element seems worth honing in on. Ant-Man and The Wasp generally tries to explain all of the bizarre sci-fi elements that it introduces, but it doesn't necessarily provide a rationale for why or how Janet has more clothing and some new weaponry when Hank finds her in the Quantum Realm. Though we still don't have confirmation of anything, it does start to seem like there might be more sentient life down there, possibly even beings who have powers similar to the ones developed by the first Wasp.
It also makes quite a bit of sense to know that the Quantum Realm will continue playing a role in the Marvel Cinematic Universe when we weigh the fact that other MCU movies will reportedly incorporate it into their own stories. Avengers 4 will reportedly feature the Quantum Realm in a critical role (which makes sense, as Scott is currently trapped there), and Ant-Man science consultant Dr. Spiro Michalakis has even hinted that the Ant-Man story would tie into Captain Marvel. If nothing else, we can at least confirm that Ant-Man and The Wasp is far from the last appearance of Janet Van Dyne's prison or the various elements (and maybe even characters!?) that inhabit it.
Ant-Man and The Wasp is still out in theaters, so if you have not seen it yet (or if you want to check it out again now that Avengers: Infinity War has debuted its home release) then you can check it out to see the possible tease for yourself! Looking ahead to the future, Scott Lang will return to the Marvel Cinematic Universe next year when Avengers 4 rounds out the Phase 3 slate on May 3, 2019!