I reckon they have done the simplest thing they could to get the exhaust out of the way of the driver, cut it and rotated it at the cut till its out of the way then re-welded it in that position
That way its still got the same tuned length (important on a twostroke) internal dimensions which affect the engine tune but it doesn't poke the driver in the ear.
I very much doubt that a standard pipe would fit.
Although four stroke pipes are nothing special and basically an excercise in pipe bending, two stroke expansion chambers take far and away more mathamatics to work out properly.
