My son just said to me that her kids will also die...I said they can’t do that! He said ‘that’s what happened in the comics’. I hope he’s wrong and Disney adjust that bit
From what I've read online, in the comics the twins were made from/by Mephisto and reabsorbed by him. Agatha, Wanda's mentor in the comics then erases her memory of them.
They are then somehow reincarnated as they are in the young avengers. So is vision, young loki and I think monica (she seems to have various hero names. Spectrum/Photon/miss marvel?)
There's also she hulk which there's meant to be an upcoming series being made.
Disney need wiccan and speed (billy and tommy) to be around for the reboot and I can see them aging themselves to teens next week to help in the fight. Especially if wiccan is as powerful as his mum.
We know that wanda's Vision can't survive outside the bubble. She produced him from her energy (looked like it was also the mind stone that gave her her powers too) so his consciousness is real at least.
We also know there is a new body for him to potentially use/take over so good chance he might make it.
Not seen any reference to Wanda in future series/films though so will she sacrifice herself for everyone else?
I'm also not yet convinced Agatha is pure evil, self serving yes. She was attracted to the massive magical event and wants to unlock the reason for Wanda's power because she wants to be able to do it herself.
She didn't set it up, just taking advantage of the situation. Hayward doesn't know who she is.
The question is whether Hayward himself is the baddie or if he's just working for someone else. He NEEDED wanda to get vision's 'brain' back. He told her he couldn't give the body of a sentient weapon to someone powerful enough to bring him back. He KNEW she could do that before she did. She can't bring back dead people but 'vision' was energy. His body rebuildable.
I'm secretly hoping there is a bigger baddie, maybe Mephisto (Ralph?) and that Agatha will have to help stop him. 
I also overthink everything 😂