It may be hard to learn for some people and that was clearly the easiest way to 'fix' the usability, but it surely isn't the most elegant fix.
They could have kept the arrow and used some animation to emphasize it when scrolled all the way down, or added the text next to the arrow when someone tries to scroll down further than possible. Or they could have used an animation after starting the phone that briefly shows/hints at the app list while bringing up the start screen. I'm sure there are countless ways to improve the usability while keeping the look intact.
Ideally, you'd want a signifier that communicates the affordance without having to scroll all the way down, since the real issue isn't that the users don't know what to make of the button, but that they don't know that there's something to the right and how to get there. The label on the button still won't tell them that they could have swiped to the right at any point.