I have 4500+ images on Shutterstock
I've opted out on 1st June
As my actual low income doesn't permit me to stay opt out i've decided to opt on again in October, actually I have 0 images online in my portfolio, I've tried to upload 16 new photos and they are now online, only 4500+ are missing !!
I've also asked to Shutterstock about the glitch and I had the same answer as you.
Maybe it's not a glitch and only a punishment to those who opted out ...who knows ?