Excellent, I forgot about the history diverging bit from Hand in killer7. It's long and it's been awhile since I read it, heh. I'm sure that's what we're seeing when Dan confronts Shigeki Birkin in the larger timeline TSA fits into. Makes me wonder how much this path of the killer7 has in common with what happened in the game.
Dan and Mills are alive. Curtis is presumably dead. Birkin sold out Dan to Curtis, when the "killer is dead" story had Birkin look to Dan for protection from Curtis. Also, Dan enters the Celtic Apartment from a door that makes no sense (), which I'm now convinced is a visual cue that we are not seeing the same reality we see in killer7, because if it's not that it's an annoying continuity error haha.