Application Accounting Definitions Import Options 12.1.3

When we want to import new Application Accounting Definitions, we use the Import Application Accounting Definitions concurrent request. One of the parameters for this request is Import Option. In 12.0.6 we would select Overwrite as our import option. When attempting to run this same request in 12.1.3 I have noticed that 'Merge' is the only Import Option available. After looking into this further, I have noticed that this is due to the WHERE clause in the 'Validation Table Information' window for the XLA_SRS_AAD_IMPORT_OPTIONS value set being updated to include 'AND LK.LOOKUP_CODE <> 'OVERWRITE''. Is there a reason Overwrite was removed