Hello Gopi,
/SAPTRX/DELETE_UNPR_MSG program is not looking for any events locked under /SAPTRX/LOCKEDEH table and therefore if the event data is deleted using the unprocess message program, it will keep that event message entry orphan in lockedeh table. And it will never be deleted from /SAPTRX/LOCKEDEH tables.
Specially for high volume customers, where the data retention is always the challenge, it will be best practice to use archiving programs instead standalone utility program to delete data from system. And standard EVM_WRITE program also follow residence checks and more flexibility to archive data on different selection criteria compare to /SAPTRX/DELETE_UNPR_MSG program.
Thanks,
Kinjal Rathod