I guess I'll chime in since I was catching up with the thread.
7th - Almost certainly Valravn unless WW uses this as an opportunity to show the 7th again. MC has got memories about the 7th, even when he never encountered it on that dead end. So this could be another Deus moment, since MC never actually used his memories on or connected to Deus yet he's there for the 5th Apostle stuff. There's also Nyx.
Then again, there's nothing that say Danica couldn't appear here actually. Her X mark the spot is undetectable and can rip through just about anything as long as she stares at it long enough. You can't even detect it unless she shows you first. She could definitely be a wild card for multiple apostle spots.
8th - Definitely Tiffany but could be Clark. They're both closely related so there's a chance MC sees both of them. Maybe Oscar as well. Slim chance for Dani.
9th - Eisheth since he saw her memories through her blood, which is unavoidable. It could be Henri or Elijah too.
10th - Shen is the most direct but if WW did change Aglaecwif's origin, this would be the likely candidate since she's still a Chosen of a single Apostle. Especially since she was previewed next to Shen and it wouldn't be too shocking if she actually turned him. Or, Demi, maybe.
11th - Plenty of options really. Nyx, Malik, Klaus, and Evander. Maybe Danica, though I doubt it as you can easily put her in Light or Darkness as well with her power, Cross Light. Klaus gets overlooked here, but his powers are actually pretty destructive. Not as potent as Evander but those two abilities function pretty much the same and MC actually could've did the same thing to Evander that he did to Klaus.
12th - Plenty as well. Devana, Deryl, Tanos, Rebis, Alexis and even Lucius. Deryl would actually be the boring pick here since we know about him already. I honestly don't think the dream sequence would be interesting like Alice, Michael or Ella were when we saw them. I could be wrong, but maybe Deryl isn't used here.
To be honest, I don't think we're going to even see the other six Apostles, personally. At least not via the dream. We'll probably learn about them when MC wakes up. The cult will likely spread their gospel to him like they did with Evander and Devana during the infiltration. Maybe even another Chosen, like Rebis or Aglaecwif, might encounter him. Rebis might find his birth interesting and want to compare him to his engineered creations. Aglaecwif is for obvious reasons.
That's just me though. Maybe WW just gets all of the introductions for the Apostles out of the way in the dreams now. I also could be wrong about who appears in what dream.