In my experience, you only want machine-generated values to be reserved sheet soft delete. Operationally, too many users want to delete stuff so that they can free up a user-generated value. In my service, users frequently delete their sites so that they can replace the URL/subdomain with another that they want to replace it with.

Especially when you consider foreign keys, restoration of deleted data is essentially never just setting the deleted field to null. You need a more robust system to fill in missing details or rectifying the deleted data with new data.