I believe it's not necessary to call for the references as i got my RTD without being contacting the references.Here's my timeline:
June 29th : Sent out the mail
July 3rd, 2024: they received the mail
September 5 today: No references received any calls yet, and the IRCC said on phone they have the application and messaged the office that the application is overdue and the processing times have passed, but they said it has been 3 weeks they sent that message and no reply from the office.