Keep missing pages distinct from your blog home
Missing post, category, and author pages no longer inherit the home page's canonical URL and social metadata.
A link to a page that does not exist should not describe your blog home. Confirmed missing post, category, and author pages now use a 404 title and noindex, without inheriting the home's canonical URL, description, or social metadata.
This applies automatically, with your existing custom 404 page retained. It clarifies the information served for missing pages; it does not guarantee when search engines will update their index.