Conspiracy theory is that any old roster was rushed out to fulfil the contractual publishing requirement. That gave them breathing space after the 15th to 'refine' the real one and send it out late as a 'correction'. 'Data corruption', pig's rear end!
In any event, 'double rosters' and reports of 'published roster' emails to retired crew would indicate a certain level of corporate stress; the airline's rostering system has serious IT and human error problems.