Clarification as to what's going on with the blogs:
They're being migrated to CloudFront, when making a blog post, go to origin.blog.sitename.com first. If that doesn't resolve then just go to blog.sitename.com
Login for the migrated blogs is easiest to do at origin.blog.sitename.com/wp-admin
New posts will show immediately on origin.blog.sitename.com, the link can be copied from there and posted to social media. Even though it's copied from origin, the copied link will point to blog.sitename.com and the link will work immediately even though it won't display on the home page right away.