ODM SharePoint does not synchronize objects between SharePoint source and target .
After a file is deleted at source, the next time when the migration is run, this file cannot be detected and so nothing will be done, so its corresponding file at target will be treated as independent & unrelated to source.
ODM will be able to detect this file when it still exists at source, then it will be used for checking if its corresponding file also exists at target, so if yes, then it will be skipped from migrating, else if its corresponding file does not exist at target, then it will be migrated.
Hence ODM does not retain any information coming from previous migrations.