Thank you!
This isn't formally written anywhere, but I suspect that once the faculty of eHealth program like you, they recommend you to the Grad committee. Grad committee then ensures all admission requirements are met based on the criteria set by the University. See link: https://academiccalendars.romcmaster.ca/content.php?catoid=25&navoid=4667#2.1.1_Admission_Requirements_for_Master_s_Degree
The time it takes for the Grad committee to make sure you are a suitable candidate, is responsible for the delay in sending out official letters.