Flashback Migration, how does it work exactly? (nevermind, it already happened)

I couldn't play a lot in normal Heist so my Flashback character is now actually the highest and furthest in all content. I'm currently in the SSF Flashback event on a PS4.
Will only the character and it's inventory be moved over?
Stash?
Delve?
Atlas?
Heist?

Would love to get a GGG clarification.

PS: Love the Flashback event, played in all three and this is my favorite. Especially since I love Blight encounters. It's basically the league but every zone has 2-3 random scarabs for free. What's not to love. I guess it's only so unpopular because it's close to a new league, it seems like a lesser Mayhem and people don't want to mess with the Atlas and other progress mechanics AGAIN (Watchstones, Delve, unveils). And I love the Voicework ("Heads on a Pike!" I laughed for a minute straight) and enemy designs of Heist. I hope it will reappear with some interesting gameplay at some point or as a kind of occasional Safehouse-like loot bonanza.

<edit>
And just to make sure, this evening, my Flashback SSF character will be moved to Heist SSF, right? That should be the parent league.
Will the character be locked for a time until rewards are distributed?