That is probably what happened.
See this and this from Reporter FAQ here on BOB.
By deleting the old reports and re-exporting new versions, the new versions have new internal “document ids” in the repository – so they are different documents.
And the users with old versions are referencing a document ID that no longer exists – and yes, to be safe, BusObj assumes that the documents, which were secured, are not usable – since it can no longer check whether or not the users are authorized to use them. So they have to reimport the new documents.
Anita Craig (BOB member since 2002-06-17)