Jossed: Vault 111 is another Cryogenic Suspension Vault.Perhaps that's what Vault 111's experiment was? What's more likely is the old casting leaks that people initially balked at - they mentioned that the main character emerges into the wasteland from cryogenic suspension.
Specials were generally non-canon: stuff like finding a crashed Star Trek shuttle or the TARDIS. So, time travel in a trailer? Makes more sense as an important detail.
Considering it's a sequel to a big franchise, it's abnormal to give a quick rundown of what happened in the past in the trailer, as it's usually assumed you know. The trailer keeps flashing from 2077 to whatever year it takes place in. Law of Conservation of Detail, basically.
