Thank you Doug! for some reason replacing "Last Updated By.Name" by
{$$USER}.{ID} or any other combination didn't work. LEFT(IF(LEFT(Status
History,LEN(IF(ISBLANK(Status),"-",Status)))=Status,Status
History,CONCAT((IF(ISBLANK(Status),"-",Status)),Last Updated By.Name," -
"," (",$$NOW,") | ",Status History)),2000)