Received notification to check portal via email. Wonder why it took them 5 months to send out a rejection letter

I come from different CS background (economics) and have 13-year of IT careers at a government institution. No GRE

MCS

Good academic track record

Given admission into Software Engineering, instead of Computer Science

Professional MCS. Got an email around 3 AM IST.

If unis want to reject only, they should do it sooner.

CGPA = 8.9/10

Waitlisted for MSML. Received the rejection today: "I regret to inform you that we are unable to admit you to the Master of Science in Machine Learning program at Carnegie Mellon University. As indicated in my previous emails, your application was very strong and we reached this decision due to our program being capped at just 35 students out of an applicant pool of over 1200. Our yield this year was higher than usual and so we were unfortunately not able to admit anyone from our waitlist. Thank you again for your patience, understanding, and assistance during the long admissions process, and once again, we are sorry you were not included in the admitted students. We wish you the best in your future endeavors."