DROP USER weirdness in 7.2.1

I have encountered unexpected behavior of DROP USER in 7.2.1.

One would normally expect, that when DROP USER someuser is issued, all
associated data structures will be readjusted, especially ownership and access
rights.

This however does not happen.

After droping an user, that had ownership of tables, pg_dump complains :

[...]
pg_dump: WARNING: owner of data type table_one appears to be invalid
pg_dump: WARNING: owner of table "some_seq" appears to be invalid
[...]

The access rights to those tables remain

database=# \z table_one
Access privileges for database "customer"
Table | Access privileges
-------------+------------------------------
table_one | {=,98=arwdRxt,maria=arwdRxt}
(1 row)

There is no way to remove rights of this 'user' 98 using REVOKE etc.

Perhaps full dump/reload will remove the rights, because that user will not be
found, but restore may fail due to the error conditions.

Any resolution for this?

Regards,
Daniel