Hi, john_f2004 .
Unless otherwise specified, App Volumes updates such as Update 1 can be treated as a replacement for its previous release. App Volumes administrators can now disregard App Volumes 4 (4.0.0) as App Volumes 4 Update 1 (4.0.1) is now generally available and replaces its predecessor.
Hope this helps provide some clarity to you and others.
Thank you for asking.