Brain in Jar Character from the first trailer Spoiler possibly.

[caffeine4671]

Here's another theory: The character in the teaser is having a dream/hallucination while being assimilated by the WAU. As he's dying, the WAU/structure gel is corrupting his mind, thusly why we see the room around him crumble away to reveal an body-like passageway. Maybe IRL raznik and nameless have structure gel enterign through their nose/ears/orifices and are dying.

Plausible, except when WAU gets to your organic body, you NEVER die. It's a core principle of SOMA.

No, no, I meant dying as in, before the structure gel got to him.The character seeing his brain being ripped apart by metal arms is his remaining mind and concsious self's way of representing the corruption that's taking hold of his mind and body. IRL, raznik and nameless could be just laying unconcious in normal beds at pathos 2 that are being corrupted by structure gel slowly. Hallucinating the brain-in-jar experience as a way of visualizing what's happening.