"I think Kevin [Feige, Marvel Studios president] wanted to make sure that there was a reason for it, that it made sense. And I hope that's what we did." This quote from Jac Shaeffer makes me think it is a meta casting that makes sense in the show.

So this will allow Quicksilver to possibly be rewritten into the MCU timeline, while not merging/connecting/bending with the Fox-Men franchise.

I think that when Wanda said to Billy that she has a brother that she doesn't see for a long time and she is sad about it, Billy recreated her brother the way he imagines and made him visit Wanda in the end of the episode.

Maybe, not sure. The silver hair is very specific.

To be honest, his hair doesn't look like Fox-Men's hair. It is a mix of them both, but mostly from MCU Pietro.

Why are we talking about hair?

@Marvelus I didn't mention that. I meant: If Pietro was recreated by Billy in the way he imagines, as the theory of user BkBraga says. How would Billy know Pietro's hair color? It is a specific detail. It would be a coincidence.

@Marvelus Which movies is he called Peter vs. Pietro in?

He is called Peter in the Fox-Men movies and Pietro in the MCU

@David Kaique I was just adding more to the conversation, not replying specifically to your message. I just think it is a meta-casting, no Multiverse shenanigans.

We don't even know if he's gonna be an actual Quicksilver lol