There's more...

The behavior would be exactly the same in a Jakarta EE 8 server. You just wouldn't need SeContainerInitializer and would need to change the dependencies to the following:

        <dependency>
            <groupId>jakarta.platform</groupId>
            <artifactId>jakarta.jakartaee-api</artifactId>
            <version>8.0.0</version>
        </dependency>