Articles are not threads, just like Resources (XFRM) and Media Items and Albums (XFMG) are not threads, altho, AMS Articles and XFRM Resources can have associated discussion threads (optional on a per category basis).
So the answer is yes as long as you've configured your AMS Categories to automatically create an associated discussion thread (but keep in mind, the thread is NOT the Article). AMS does have an
XenForo's Find New System segrgates content by content type, so "New Posts" is only for posts in discussion threads, it can not fetch other content types. That is just how XenForo designed the Find New System. So any content type that implements a Find New Handler, will have its own "TAB" or "TABS" if implementing multiple Find New Handlers like XenForo Media Gallery and AMS does. AMS implements Find New Handlers for Articles and Comments, so that addons 2 Tabs to the XF Find New System (again, how XF designed it).
AMS comes with several Widget Definitions, which allow you to create dozens and dozens of unique AMS related Widgets. Any widget created in the XF Widget System can be displayed anywhere.
The reason I ask is that I use the Latest threads Widget and I would like to have new articles listed with new threads when my users look at the latest threads and not have to click on articles separately.
The Widget Definition that is used to create that widget, is not capable of fetching content from other content types and I highly doubt that it ever will (XF would create a new Widget Definition that allows selecting of content types). That widget definition is designed specifically for Thread and Thread Content (posts). It can't fetch Resources from XFRM nor can it fetch Media or Albums from XFMG either (nor can it from 100% of all of XF's other content types).
You can always use Thread Type "Article", however, that is nothing more than a glorified thread (post #1) but of that is all you need, then that should work perfectly for you.
It sure would be nice if XF would redesign the Find New System so that it didn't segregate content, so that you click on "Find new content", which fetches all unread content (Threads, Media, Resources, AMS Articles, Showcase Items etc etc etc) and then lets members filter the results by Content Type (and could even set which content types they wanted fetched by default). That would be more inline with Search, which default search fetches ALL content types and then each content type has its own search tab for finer controls.
Hope that answers your question.