7.2. Container invocations and interception:

When the container invokes a method of a bean, the invocation may or may not be treated as a business method invocation:

• ...
• Invocations of producer, disposer and observer methods by the container are business method invocations and are intercepted by method interceptors and decorators.
• ...

It looks like a regression introduced in this commit:
https://github.com/weld/core/commit/e084e5533e972f6420f852a2e555169ba792d675