Moving or renaming a file outside of DPL disconnects that file from the database and a few pieces of information are lost - and DPL does not yet offer any means to “reconnect” such items to the database.
As of now, DPL ingests new files automatically, whether we want it or not; moves files to the trash, whether we want it or not. A more tolerant behaviour can only be attained if DPL replaced automatic ingestion/trashing to user controlled ingestion, plus removal from the DB only, without moving assets to the trash. Such a fundamental change would be welcome in view of more robust asset management, but not necessarily welcome to all those who loathe DPL’s database. IMO, DxO will have to take this decision soon, or do as you (and others in this forum) propose: Make sidecar files more comprehensive, so that they can be used as distributed database backups. Remains to be seen if edit history will be included - not necessary imo, but others might disagree…
Read more about it in the following posts