I’ve just updated OEP-0001, the process for writing Open edX Proposals. Authors used to send announcements of new OEPs and their reviews to the edx-code Google Groups mailing list. Now the announcements will be made as posts in the Announcements - Architecture category here on Discourse.
If you want to continue to receive these announcements as emails, you can create a Discourse account and sign up for email notifications with these instructions: 🛠 How to get emails for announcements.