Okay since I just watched the gag reels/trailer once, I'm gonna rewatch it and do a thread trying to put some things together because I'm beginning to explode with all the theories and the waiting for the return of the show so
THERE WILL BE #SPNSpoilers FROM NOW ON

So, from the background and the lightning it seems to be the same scene, maybe a vampire case or something like that (notice that in the first photo there's someone with a monster mask)

This seems Dean interrogating a victim or someone related to a case and since there are three beers, probably there's Sam too in the scene.

it could be related to the flashback episode, so this could be an old friend or something

This seems, from the background, something that happened outside (the lake pictures) or inside Billie's studio since it's very white and grey in colors.
#SPNSpoilers

MY BOY SAMMY GETTING A BIRTHDAY SCENE IN THE UPCOMING FAIRY HOLIDAY EPISODE
IT'S WHAT HE DESERVES THIS RAY OF PURE SUNSHINE
#SPNSpoilers

This is the same scene settled in Billie's studio, prob. there's a fight between her and the Empty. Billie will be prob. possessed by the Empty since in the runbr trailer she doesn't have her ring anymore and her hand it's covered in a liquid similar to the Empty one
#spnspoilers

(what if Chuck brings the Empty to his side promising him Castiel? so he can sleep again?)
There are endlessly theories and possibility to this scene, we'll find out when the episode airs
anyway, this is the frame where Billie's hand is covered in a liquid

#SPNSpoilers

that scene is could be happening in the same scene as this, where Cas and Sam fight with Possessed!Billie

this is the same scene with Dean&Sam slamming down a door with machetes in their hands, to slay vampires
#spnspoilers

this could be in the next episode because the jacket Jack has it's the same in the last scene of the last episode when he got his soul back.
#spnspoilers

This frame is for sure post episode 18, because Dean has the same jacket of episode 18 and the handprint of Castiel on his shoulder, also the light is the same. plus, his posture is the same as int he photo Jensen posted.
#spnspoilers

We can't see his shoulder from that frame but the clothes are the same of this scene, the goodbye of Cas in ep18 by the Empty.
The major theory is that Cas will leave a bloody handprint on Dean's shoulder, to recall the time they met in hell and Dean was saved.

There's also this scene in the new promo with Sam&Dean, and Dean has the same clothes but no handprint, so it could be one of the first scenes. it looks sad, kind of a goodbye or a speech about keep fighting.

In the new promo we have Cas burying something. It's at a crossroad and we have Misha's photo from a while ago as if it was a deal.
it looks photographed from another angle from the frame of one of the trailers, it's linked to a still from ep15x15 cause of Jack.
#spnspoilers

the first photo could be a symbol to jack and the rest of tfw, leading to separate ways at the end. Also, Jack has the same jacket of the frame with Cas, which seems a foreshadowing speech scene about goodbyes or smt like that. and I'm already in pain.

Dean here has the same red shirt of the sneak peek.

#spnspoilers

Same grey jacket, so, scene between Amara and Chuck.
Also, Emily, give me a small percentual of your beauty.

same scene, Dean tries to break Jack's handcuffs, (WHY MY RAY OF SUNSHINE IS HANDCUFFED LET HIM GO YOU MONSTERS)

Okay the major scenes are done for me, there are other frames with Charlie, whom is coming back, with Donna hugging Sam, and the flashback episode of the bros.
There are also frames with God snapping his fingers in Heaven (What if he destroys it? causing the last big damage?)

and there are scenes with Chuck in the bunker, in one he's saying "They think they can kill me?" to someone, my guess are or Amara or the empty.
So, in the end, we have a loooooooooot of things coming in the seven last episodes! Prepare for the ride!

Also, let's not forget that probably we didn't anything from episode 19-20 because they were yet to film and now they are probably finishing them; So the trailers will probably be until episode 18, with maybe some shots from episode 19.

God, what a thread

ops, I forgot: in one of the short trailers there was a little frame of a flashback of Castiel, probably from the episode with Uriel.