My wife can talk to someone in charge at IOM today and she got more informations. First, here in Saigon, they do not make the analysis by their self and that why my wife needed to go in an other place (referred hospital) to do the sputum test. So they will not notify IRCC cause they will get the result in minimum 8 weeks.
So I will send a message to IRCC that the test is in progress and that IOM will provide the results when the hospital in charge will send the results.
About the timeline:
For us, it's mean that IOM will receive it at the end of October or in November. So, if it show a negative result, I add one month for Singapore notify that they received it and, without other request, I do not expect PPR before January.
Good luck !