If we're going to say hot dog, we might as well be able to say bratwurst -_- . Come on people, just answer sausage and leave it at that. Sausage is universal.
A "banger"...? That must be British. I'm American and have never heard that before.
It is British. I suppose enough people from the UK wrote in to get them to change it. There are other terms that are only used in the USA that aren't used abroad ("a candy" instead of "a sweet" for example) that I see a lot of complaints about in the comments.