Execution Plan Warnings cardinality xml data type I have the following statements:

-- 1st
DECLARE @AuditParameters XML = (
    SELECT
        1 AS AccountID,
        2 AS CategoryID,
        3 AS CategoryAttributeID,
        '4' AS SyncBatchGUID
    FOR XML PATH(N'Parameters'), ELEMENTS XSINIL
)


-

-- 2nd
DECLARE @AuditParameters XML = convert(xml, (
    SELECT
        1 AS AccountID,
        2 AS CategoryID,
        3 AS CategoryAttributeID,
        '4' AS SyncBatchGUID
    FOR XML PATH(N'Parameters'), ELEMENTS XSINIL
))


Both statements result in the same execution plan, however, they display the warning message 


  Type conversion in expression (CONVERT_IMPLICIT(xml,[Expr1004],0))
  may affect "CardinalityEstimate" in query plan choice.


You may note I have tried to convert the second statement to XML and yet I get the same warning message.

How can I get rid of this warning message on the statement above? 

Thank you
Add TYPE to return XML from the inner query rather than a string

DECLARE @AuditParameters XML = (
    SELECT
        1 AS AccountID,
        2 AS CategoryID,
        3 AS CategoryAttributeID,
        '4' AS SyncBatchGUID
    FOR XML PATH(N'Parameters'), ELEMENTS XSINIL, TYPE
)