Your bridge would span, what, 2000 miles? At a conservative 1 billion per mile over open ocean, that would be 2 trillion dollars, which is roughly the GDP of Germany.
Ships would still be competitive with rail and trucks.
Flying would be more competitive than driving for passengers.
No one care whether the Newfies are less economically depressed.
I wouldn't count on such a bridge being built.
Yeah, that was the whole point of building ships in the first place (they could go up/down rivers cheaper than land-base modes of transportation, which is one reason why cities built on rivers grew so quickly)