I will provide details for the next notification I recognize not to have received (I do not recognize all missing notifications).
The latest incident where I believed to have missed a notification is https://community.plone.org/t/upgrade-to-5-2-failing-with-iatcttool-has-no-attribute-iro/8909/9. However, after rereading the post, I recognize that I might have been wrong (the information I missed was not prominent and far down the post - I might have gotten the notification and missed it in the message).