I wish I had taken a screenshot but I forgot... Something really silly happened to me in my Portugal game. Great Britain owned the eastern half of the northern coast of South America. I am allied with Great Britain. I get a message from Great Britain, a call to arms to help them in their war on.... England! I thought that was pretty funny, so I checked the British Isles and that was still under control of Great Britain. So I'm looking around the map and I see it, Great Britain's colonial holdings in South America, which had been under rebel control for a few decades had revolted and formed England! And their national religion was Protestantism, despite the province religions all being Catholic! So i declared war, easily swept through them and controlled all their provinces. I ended up gaining a few provinces and vassalizing them. A couple seconds after vassalizing them France declares war on them, but oops too late, Great Britain, still at war with them, takes over their sole province and eradicates them.
I dunno if this is normal, but I just thought it was hilarious, and although it doesn't seem realistic, it was funny to imagine a group of Protestants taking control of these Catholic provinces in South America and declaring themselves England.