Resident Evil: biohazard is due out next week, and while we don;t know much about Ethan's story yet, we know that there will be some extra story content coming after launch.
Not too much is known about the Not a Hero DLC yet, but Famitsu (via Siliconera) tells us that the new story will be different from Ethan's nightmare that we'll see at the end of the main game. The DLC will be free and released sometime this Spring.
Resident Evil: biohazard is coming on PS4, Xbox One and PC on January 24. Capcom just released a new trailer for the game late last week.