You're only seeing the very first steps, but not noticing where the intent is. Building an entirely new replacement implementation will fight the battle of ado

You're only seeing the very first steps, but not noticing where the intent is. Building an entirely new replacement implementation will fight the battle of adoption. By wrapping initially an abstraction around the existing code, you can then go back and replace the original while at the same time, keeping everything relying on the original working. If you see Marco's initial work as a "shim" to enable replacement, it makes a lot more sense.