Previously (below version 9.7) granting DBADM granted all the database authorities explicitly - specifically these ones

BINDADD
CONNECT
CREATETAB
CREATE_EXTERNAL_ROUTINE
CREATE_NOT_FENCED_ROUTINE
IMPLICIT_SCHEMA
QUIESCE_CONNECT
LOAD


And when you revoked DBADM, these guys would still linger on! In 9.7 this changes - granting DBADM still gives you all these authorities ..but implicitly. You will not see them in the system catalog SYSCAT.DBAUTH view being granted. Nevertheless you will have them. And, naturally, when you revoke DBADM, they will be gone along with DBADM - just the way it should have always been..