Flashbacks usually start when it's a Dire Situation,
And it must Involve the Character who was Inspired by Inspirational Figure or Deceased Character from said Backstory,
So imo God Valley Flashback is Part of Loki Flashback & it will Start when Loki is Endangered,
Not just that, but it usually starts when They are facing Main Villain,
So i wonder who's gonna show up soon to face Monster Trio