The CDI 1.1 specification says about a @Specialized bean:

"When an enabled bean, as defined in Section 5.1.2, specializes a second bean, we can be certain that the second bean is never instantiated or called by the container. Even if the second bean defines a producer or observer method, the method will never be called."

JavaDoc of @Specializes even say that the superclass bean is "disabled".

However, WELD do call observer methods of the superclass.

I have a "Java EE concepts" project that execute a series of Java EE tests using Arquillian and the test that test the behavior of @Specializes and supposedly disabled observer methods fail.

The project is Maven based and has two profiles for WildFly- and GlassFish remote servers. Feel free to clone and execute.

Read more on this error in the JavaDoc of the test class:

https://github.com/MartinanderssonDotcom/java-ee-concepts/blob/master/src/test/java/com/martinandersson/javaee/cdi/specializes/SpecializesTest.java