I have been using the News app quite frequently since it launched and relied on the Widget to keep me up to date. To my knowledge, the widget on iOS 9 matched the content you favoured e.g. I would get articles relating to Politics, or Breaking News. For iOS10, it seems to match it to the 'Top Stories' and half of the column for 'Trending', which to be frank, relates to things of no interest to me (i.e. Kardashian gossip, Buzzfeed click-bait articles etc). This problem only relates to the widget; the app itself is fine when you open it.