There appears to be a problem with Blog publication. Edits seem to be published, even if you use the save or save & continue action. Also if a blog is set up to allow co-authoring, email notifications state that edits were performed by the original author.
The consequences are that a lot of update notifications emails are flying around with misleading information. Not withstanding the issue about publication before publication action is made.
Blogs don't allow co-authoring of posts, only one user can create/edit a blog entry. Could you clarify the issue you're having or provide a repeatable sequence I can follow that demonstrates the blog behavior you are seeing?
I'm also trying to repeat the email notification. No luck so far but I have a few more permutations to test.