P5R Story Theory
Kasumi will most likely join your party during Sae’s palace. This is because all of the footage of her awaking looks like Sae’s palace. The story will be mostly be the same with the only difference being that Kasumi is there now.
The new story is probably going to start 1/2 right after the New Years event. For about a week, we’ll see the phantom thieves dreams become real. After we see all of the dreams, Akechi reveals to be alive in some Avdol level bullshit and probably was a hobo for basically a month. He probably won’t be playable during the Yaldy fight because he didn’t appear during the New Years event. So yes, Akechi saw the world basically ending and was like “This is fine lol” and didn’t help. He’s going to tell you to meet him in a week if you want to save your friends. This probably could lead into a bad end if you don’t go help him.
There are probably two “palaces” you get to explore in the story. The stage looking place and white mementos. The stage place will probably be the thieves’s palace if that makes sense. Basically all of the thieves have separate sections to each of them and when you complete a section that character will be added to your party. The theater will probably be a bunch of reused mechanics and remixed bosses from previous palaces. (In PV#2 we see a remixed boss fight with the art guy I forgot the name of). The party will probably start off as just Joker and Crow.
White Mementos will probably be unlocked after gaining Morgana. The bottom of White Mementos is “Heaven” (Based off of Harry Type-C’s translation) and is probably where we fight the final boss. The end of PV#2 we see the phantom thieves panicking and telling Joker to stop. This could mean two things. A) Joker is destroying the dream world. Or B)Joker will be Door-Kun 2: Electric Boogaloo.
While option B seems to make no sense. It actually is probably the most probable outcome. We hear Kasumi’s voice at the beginning of PV#2 and he’s saying (Based on Harry Type-C’s translation), “The door had always been sealed, it’s finally opened” and in response Egg Boi says, “It’s all thanks to Onii-San, isn’t it?” The door that Kasumi is talking about might be Blue Jesus’s door. And someone must of removed him. And apparently Jose’s “Onii-San” did it. Onii-San means “Older Sibling” Jose looks like a velvet room assistant (minus the clothes) so the Onii-San might just be Elizabeth. I think Elizabeth removed Door Jesus from the door but because no one is sealing the door Nyx is coming back and Joker sacrifices him self to evolve from a virgin chair to a Chad door. This may seem like completely out of place in Persona 5 but the major theme is desires. And people can desire death. So it works. Also Blue+Red=Purple, purple is a color associated with Royalty, Royalty-> Royal, Persona 5 Royal. I win. Praise Door-Kun.