Yeah, Newfies speak English just like Scottish speak English. Those words might be English, but it's the phrasing that makes no sense.
Having grown up with so much predominantly east coast originating comedy, and around so many Newfoundland diaspora, I guess it never occurred to me that there was any real negative connotation whatsoever, beyond poking a bit of fun at some of the presumably antiquated cultural stereotypical differences via self-deprecating jokes that most people from smaller places have their own versions of and don't take too seriously.