<DAT_ABC>2021-06-08T16:17:12.341</DAT_ABC>

LOAD_TO_ABC_DATE   TIMESTAMP WITH TIME ZONE     PATH 'DAT_ABC',

, CAST (LOAD_TO_ABC_DATE AS DATE) LOAD_TO_ABC_DATE

INSERT INTO TABLE1
SELECT
...
, CAST (LOAD_TO_ABC_DATE AS DATE) LOAD_TO_ABC_DATE
FROM XMLTABLE(
...
COLUMNS 
...
LOAD_TO_ABC_DATE   TIMESTAMP WITH TIME ZONE     PATH 'DAT_ABC',
...
)

<xs:element name="DAT_ABC" type="xs:dateTime" nillable="true">

select DSDecodeDate ('2021-06-08T16:17:12.341') from dual;

select 
 DAT_ABC a, cast(DAT_ABC as date) b
from xmltable(
         '/A'
         passing xmltype('<A><DAT_ABC>2021-06-08T16:17:12.341</DAT_ABC></A>')
         columns
            DAT_ABC timestamp with time zone path 'DAT_ABC'
         );

WITH XMLTEST(DATA) AS
     (SELECT XMLType('<TestData>
       <trade>
         <GenTest>
           <Id>IDVal</Id>
         </GenTest>
         <DateTest>
           <Date>2021-06-08T16:17:12.341</Date>
         </DateTest>
       </trade>
     </TestData>') data FROM dual
     )
SELECT 
    t.id
    ,to_date(t.testdate,'YYYY-MM-DD"T"HH24:MI.SS.FF3') 
FROM XMLTEST xt
  ,XMLTable ('/TestData/trade'
      passing xt.data
      columns
      id      varchar2(10) path 'GenTest/Id',
      testdate  varchar2(100 char)          path 'DateTest/Date'
      ) t
;

WITH XMLTEST(DATA) AS
     (SELECT XMLType('<TestData>
       <trade>
         <GenTest>
           <Id>IDVal</Id>
         </GenTest>
         <DateTest>
           <Date>2021-06-08T16:17:12.341</Date>
         </DateTest>
       </trade>
     </TestData>') data FROM dual
     )
SELECT 
    t.id
    ,to_date(t.testdate,'YYYY-MM-DD"T"HH24:MI.SS') 
FROM XMLTEST xt
  ,XMLTable ('/TestData/trade'
      passing xt.data
      columns
      id      varchar2(10) path 'GenTest/Id',
      testdate  varchar2(100 char)          path 'DateTest/Date'
      ) t
;

select cast(to_timestamp('2021-06-08T16:17:12.341','yyyy-mm-dd"T"hh24:mi:ss.ff3') as date) d from dual;

SELECT * FROM NLS_SESSION_PARAMETERS;