I think the point is that NewsPublisher, a front-end method of adding documents such as blog posts, is not included with the standard distribution of MODx 1.0.0. The
release notes say this is because it cannot cope with template variables (which you need e.g. for tags).
The MODx 1.0 sample site has a blog, but instead of using NewsPublisher you are now expected to be a manager user and to create your blog posts like other documents on your site, using "Create resource here" in the blog posts folder. This is described in the text on the blog page. The site has a template variable called documentTags for a space-delimited set of tags for posts.
I have not seen this documented - MODx 0.9.5 (which did include NewsPublisher) seems to be the latest version covered in the Wiki articles on blog-building. I could add a note to the top of the relevant articles (

though I’m happy if someone else gets there before me)

KP