At the end of Ant-Man, Hank Pym showed his daughter, Hope van Dyne, the prototype Wasp suit that was originally designed for her mother, Janet, but now belonged to her. Originally it was considered having Hope jump into action for the first time as Wasp in 2016's Captain America: Civil War, but it was later decided to push her heroic debut back for Ant-Man and the Wasp. However, new concept art has appeared online giving us an idea of what Wasp's participation in Civil War would have looked like.
Marvel Studios Director of Visual Development Andy Park shared this Captain America: Civil War artwork on his Twitter page, showing Ant-Man and Wasp tangling with Hawkeye while Scarlet Witch, Captain America, Black Panther and Winter Soldier are doing their own thing in the background. In case you're wondering why this particular brawl has unfolded, given that Ant-Man and Hawkeye were on the same team in Civil War, this scene came from an earlier version of the movie where the teams were divided differently.
As you can see, in this version of Captain America: Civil War, Hope van Dyne has enough Wasp experience under her belt to shrink and shoot energy blasts. No doubt she would have been a formidable opponent, and part of me wishes that this sequence was animated. However, given how packed with characters Civil War already was, including introducing Black Panther and Spider-Man into the Marvel Cinematic Universe, I don't blame Wasp for being left out of the first Phase 3 movie.
Evangeline Lilly noted earlier this year that the rationale behind leaving Wasp out of Captain America: Civil War was because the Marvel Studios bigwig wanted to dedicate an entire movie to the heroine's "introduction" rather than just having her be a "side note" in a larger story. That's also the reason why Wasp wasn't in Avengers: Infinity War, although it turns out there was also a story reason for that, as most of Ant-Man and the Wasp takes place before Thanos and his minions arrive on Earth.
So ultimately we had to wait two extra years to see Hope van Dyne get her superhero on, but that time finally came this past summer in Ant-Man and the Wasp, where she and Scott Lang had to face off against the likes of Ghost and Sonny Burch, all while trying to finally free her mother from the Quantum Realm. The sequel also addressed Hope's absence from Captain America: Civil War by mentioning how Scott went off to help Team Captain America without her, which is the reason why a rift had grown between them.
Sadly, Ant-Man and the Wasp ended badly for Hope, Hank Pym and Janet van Dyne, as they were turned to dust by the Thanos snap while Scott Lang was in the Quantum Realm. However, Evangeline Lilly is confirmed to appear in Avengers 4, which comes out on May 3, 2019. So whatever the Phase 3 capper has in store, we can take comfort knowing that Hope's story isn't over yet.