So, um, along with information on the upcoming Denmark and Sweden character song CD, Animate also released information on limited edition merchandise that will be released from July 30 - August 23, 2015. Among the announcements was something rather notable. Specifically, the button in the bottom left corner of the above image.
While the other characters are fairly recognizable, this one is actually someone we haven’t seen before. In fact, the name listed - グリーンランド - translates to Greenland.
So it looks like Hetalia may have introduced a new character through a… merchandise announcement? I guess there’s a first time for everything.