We've known for several months that Joe Locke will play Wiccan in Agatha: Coven of Chaos Darkhold Diaries, but it appears Marvel Studios has plans for Billy Kaplan/Maximoff beyond the WandaVision spin-off.
Billy is, of course, the name of Wanda Maximoff and The Vision's son. Alongside his twin brother, Tommy, they were wiped from existence when the Scarlet Witch took down the Hex surrounding Westview in WandaVision. While comic book fans know their teenage counterparts eventually become the Young Avengers known as Wiccan and Speed, it's not quite that simple.
When Wanda lost her children on the page (after similarly creating them through Chaos Magic), their souls inhabited the bodies of Billy Kaplan and Thomas Shepard. So, they both are and aren't the Avenger's kids, but thanks to their "mother," the duo was granted incredible powers.
Recently, there have been rumblings Billy's soul will take charge of the body of a dead LGBTQ+ teenager, prompting fans to express concerns the Scarlet Witch and Vision's son will only be gay due to the influence of his host.
As a reliable scooper has now explained, Billy Maximoff is very much in love with his boyfriend Eddie, though those claims about his soul taking over an empty shell appear to be correct. That's an interesting approach but one that lines up with what we saw in the comics.
Agatha Harkness clearly takes an interest in Billy, no great surprise when he's the powerful son of the Scarlet Witch. It's unclear whether Tommy will show up as Speed but we've heard nothing to suggest the character has been cast...yet.
As for Agatha's role in all this, it's possible she wants Wiccan's abilities for herself or hopes to train the boy in an effort to make things right after previously crossing paths with Wanda. It depends on whether she's remaining on a villainous path or will find redemption in this spin-off.
Marvel Studios appears to have no concrete plans for the Young Avengers in the MCU. Instead, it seems these younger heroes will just form part of the next generation of Earth's Mightiest Heroes once we bid a final farewell to the original six at the conclusion of the Multiverse Saga.
Agatha: Darkhold Diaries doesn't currently have a premiere date.