The Marvels was released last November to so-so reviews (it has 61% on Rotten Tomatoes) and a dismal $206.1 million at the worldwide box office.
There are plenty of possible reasons why the sequel bombed, but after Captain Marvel made over $1.1 billion in 2019, its dismal performance greatly surprised the majority. While Captain Marvel 3 is likely off the table, plans for Carol Danvers supposedly haven't changed.
According to The Cosmic Circus, "Carol Danvers' role in the Multiverse Saga moving forward has not been diminished, nor will it be toned down due to The Marvels underperforming."
As for what role the hero will play, it sounds like she's devoting her time to investigating the Quantum Bangles, their origin, and whether they're capable of opening a doorway which can bring Monica Rambeau back to Earth-616. Photon was left stranded in an unnamed alternate reality with the X-Men and this very much sounds like the groundwork is being laid for an Incursion.
For what it's worth, with frequent Brie Larson collaborator Destin Daniel Cretton back at the helm of the Shang-Chi sequel, we've heard there may be a place for Captain Marvel there due to the Ten Rings' apparent ties to Kang and the bangles.
The site was also asked about whether anything is in the works with Tessa Thompson's Valkyrie. We last saw her in The Marvels too, though it's widely believed Marvel Studios cut any hints of romance between the two characters for fear of backlash.
"As for King Valkyrie, I haven’t heard much about what role she will have to play in the Multiverse Saga as of yet, but there is something I heard through the grapevine about Thor 5 and her connections to Valhalla," the site explains. "So I’d suspect her story to continue there."
We caught a glimpse of Valhalla in Thor: Love and Thunder's post-credits scene; if this is handled well, it could lead to the return of Odin, The Warriors Three, and even the Mighty Thor.
Last November, Larson said "there is still so much inside of Carol" to explore in future movies.
"I feel like getting to be on this team just cracked her open in a way that she hadn't been and I really loved that for her," she added. Asked specifically about any future MCU project she will appear in, the Oscar-winner responded, "I don't want Marvel to come for me. But there is something. There is definitely something, to answer your question, that I would want to say, but I am not going to."
Stay tuned for updates as we have them.