Notes and findings:

• It seems that Weld started to distinguish MDBs in BeanManagerImpl.createInjectionTarget(EjbDescriptor<T>) long time ago (Weld 1.1) probably to fix a NPE caused by the fact that there is no bean an MDB (that is non-contextual object), see also https://github.com/weld/core/commit/cc2d69c65f22cc7a5dd384f85a3712e3fe2f8d97 and WELD-444
• However, WeldManager.createInjectionTarget(EjbDescriptor<T>) javadoc is clear that it "should only be used to create an inject contextual EJBs", for non-contextual EJBs one of WeldManager.fireProcessInjectionTarget() methods should be used. So I see inconsistency between javadoc and docs too.