In general, waitlist admits will not be posted until after the SIR deadline since they need to know how many spots are available.
The number of admits will vary from year to year so there is no way to know your chances.
Waitlist data for the last 3 years from the CDS.
2023:
Number of waitlisted applicants: 1807
Number of opt ins: 925
Number admitted: 791
2022:
Number of waitlisted applicants: 10,742
Number of opt ins: 4468
Number admitted: 381
2021:
Number of waitlisted applicants: 3996
Number of opt ins: 1851
Number admitted: 152