To understand why an "Update" is necessary, you must understand the disastrous history of Irreversible on home video.
Irréversible (2002): Exploring the Dual Experience in 1080p irreversible 2002 dual 1080p upd
The early scenes use a spinning, unstable camera and low-frequency "infra-sound" noise (28Hz) meant to trigger nausea and anxiety. To understand why an "Update" is necessary, you