Is Captain Marvel being recast?

Yes, Brie Larson is still Captain Marvel in the MCU and will remain so for as long as she and Marvel Studios wish to bring the character back. She has not been replaced and will indeed reprise her role as Carol Danvers in upcoming sequel The Marvels.

Why did Captain Marvel get recast?

The actor was originally cast as Maria Rambeau in Captain Marvel, but had to drop out due to her scheduling conflicts with Netflix’s She’s Gotta Have It, and the role ended up going to Lashana Lynch.

Did MCU recast Brie Larson?

It was a surprise for Marvel fans when instead of Larson it was Alexandra Daniels that voiced Captain Marvel, and then later when Hudson Thames picked up the vocals of Peter Parker AKA Spider-Man.