Newfies like to feel special, so they say they're not part of the Maritimes.
I'm not entirely certain, but I believe that because we're up closer to the Labrador Strait, that brings us away from the Maritimes. Wikipedia says it's because the Gulf of St. Lawrence separates us from the maritime provinces.
That's... Hardly wanting to feel special. It's
geography.
Anyway, accents very much differ based on where you go. It's different between here (St. John's, NL) and Charlottetown, PEI, between there and Halifax, NS, ad nauseum until we get to BC and the Territories. Hell, in some provinces, there's a wide variety of accents, and case in point, even on the Eastern coast of Newfoundland, there are probably three or four distinct ones ("townies" and "baymen" are the major ones where there are accents, and some people will say that within different parts of the city, you'll hear different accents).
So yeah, from what I've read/heard, the whole "stereotypical" Canadian accent has its roots mostly in the West, though I've been told that there are those on the Western coast of Newfoundland that say "aboot". Mostly, I'd say, it's an amalgamation of many different accents throughout all of Canada. And honestly? To call it a Canadian accent is like calling a deep Southern accent an American accent.
XD "Sarry" isn't the "proper" pronunciation though. That would be a pretty good example of an accent in motion. X3 It's kind of funny, that's how some people pronounce it here, too; "Sarry", "Tamarrow/Tamarrah", "Tim Harton's" (though usually just Tim's)... I used to be really bad for that when I was young, until I started to disassociate myself from the accent.