Cal Poly Slo Waitlist Acceptance Chances

I applied to SLO for Mech Eng and got wait listed. I have a 4.3 GPA, 1360 SAT, 32 ACT, took all the AP classes I could and passed all of the AP exams, and am taking an engineering class at my HS. I also have good volunteering hours. All of these stats were average stats for the 2016 acceptance. What are my chances of getting into Cal Poly SLO. I got into Cal Poly Pomona, UCSD, UCSB.

Depends upon how many accepted ME students SIR by May 1 to open up spots, so no way to tell.

I also got waitlisted for engineering but in Aerospace. So the waitlist process may not start until pass the May deadline or is it if the decisions of declines start to roll in?

I am not in admissions but since SLO was overenrolled last year, they will probably wait until after May 1 to ensure they meet the targets this year.

Freshman candidates on Wait List will be notified of the final decision regarding their Wait List status by May 15th, while transfer candidates will be notified by July 15th.

I am a parent and appreciate the clear answer so much @College123411