Part of the question about the ordering of posts on a website comes down first to what the actual content is. Is it posts, pages, articles about particular topics, short notes?
Most blogs typically default to a particular time ordered display, but also provide search and archives for content by topical headings (tags/categories) as well. Digital gardens and wikis are set up with no particular hierarchies and one is encouraged to wander. Most social media notes and photos are created in a time only order.
There aren't enough online zettelkasten yet to look at what that might entail, though affordances there are likely to be similar to that of digital gardens which let you pick out something via keyword and then follow links from one thing to the next.
These are interesting questions for publishers as much as they are from anticipating what one's intended or imagined audience might be looking for.