On that toggled list, I think it describes the moves as they currently are (Gen V at the moment, but soon to be Gen VI). This is because that list is simply when a move was introduced, not what it was like at the time. The same hold true for Bite and Sand-Attack, which were also Normal moves in Gen I. On the move's actual pages it should say under 'Changes' that the move used to be Normal type.
That brings me to another point: the move page for Karate Chop doesn't mention that it was Normal type in Gen I(the others do, though).