I think we might be saying similar things.
On /latest (that has all the visible topics you have access to) new/unread/unseen/top/hot/posted/bookmarks are still all ways to sort or filter the big list of everything. As Nolo says, only ‘categories’ takes you to a different page entirely.
So this can feel like top level navigation rather than a sorting/ordering/filtering option. (That is, they feel like they’re taking you to a different place rather than changing the result list)
And then within a category there are certain options added by customisations that can also blur the line too and make it less easy to appreciate that latest/unread/etc are sorting/filters for the category view