I know who the Next Killer is.

Detention has always been in the gamefiles and the wiki is fanmade as well. Not saying it's not trustworthy but you should refrain from seeing the wiki as a place where leaks happen. There's also a page about the Actor which should have been Ghostface with a shapeshifting power (which is totally fake).

EDIT : That article was deleted since Ghostface's release but my point still stands.

What if we are thinking wrong about "The Teacher". Someone earlier said that they could be codenames. "The Huntress" was called "The Bear" before release too. So what if the teacher could actually be something like "The Nun" Like... you know. Valak, or some ######### xD