I think she’s right and she’s wrong at the same time if it makes sense. I think “everyone” dies but reality is altered in a way. My original prevailing theory from the jump was that things get restructured to where everyone is present for the battle of New York and all the liberties that were taken are retconned like Spider-Man and Captain Marvel being around from the beginning. Peter sewing his own suit for the crybabies, etc. Ironically Cumberbatch being the only one to have seen the majority of the script, he was the only one mentioning the “multiverse”. This universe’s heroes all parish but their is a parallel universe created with everything similar sans minor details. I think that’s how the actors are able to walk away from the roles if they want to but still leave the door open for them to return. It’ll be like the status quo being restored with Thor having long hair and Mjolnir, Asgard still being around, Captain America still being righteous as if they never experienced any of those things from past films but we the viewer know those things that have taken place and see how they reacted. The characters that lived may have their consciousness transferred. The characters that died wouldn’t and would pick up right where they left off at the end of Avengers 1 or something. Think Thor dying and not being cognizant of anything that happens after A1 in the parallel universe but Spider-Man living and being able to escape everything that went wrong in the previous universe like Aunt May finding out he was Spider-Man.