Available for free via Samsung's Theme Store, the new themes (11 of them - for now) seem to have pretty simple designs, though that's not a bad thing. These themes only show up if you're visiting the Theme Store on a new Galaxy A smartphone, including the Galaxy A3 (2016), Galaxy A5 (2016), or Galaxy A7 (2016). At the moment, it's not clear if the themes also work on the Galaxy A9, but we assume that they do. After all, the A9 is newer than all other Galaxy A handsets.
As you may remember, Samsung started offering TouchWiz themes last year with the introduction of the Galaxy S6 and Galaxy S6 edge. It looks like plenty of users are appreciating Samsung's themes, as they can dramatically change the aspect of TouchWiz.
Have you used any of Samsung's themes until now (of course, this implies owning a Galaxy smartphone)?