The notification area is for news, the tray area is for applications' status. Having a notification notify about status might be okay in cellphones, which have a different UX and runtime model, but is redundant on PC.
The concern about shutting down all notification area items is valid, especially for an AV. The built-in notifications are on by default, and are assumed to be on, and there's no guarantee Avast won't utilize them for more important news at some point in the future.
This notification should disappear when one clicks "dismiss" for the first time, with a setting to opt-in later on.