Its not cloning exactly. Its evolution.The tree has evolved beyond Starswirl's intentions. STarswirl was, and likely is sitll, an instrument of order. but order alone is not enough, In order to stop the pony of shadow, Starswirl sacraficed himself and his allies.But the tree is about creation and evolution. How many foes have become allies now? Because the tree is not Light. It is a mix of light and darkness, order and chaos.The pillars of light planted a seed in a chaotic forest that could not be controlled, and from this marraige of order and chaos, grew Harmony.Here is something to think about. Twilight mentions how the elements would lose all thier strength and prehaps vanish if they banished the pony of shadows into the void…Celestia performed banishment magic too on nightmare moon. PERhaps not as powerful as the pony of shadows at his prime, but powerful.And when twilight found them once again, they were all but stone, lifeless. And they were broken. True the element of magic had seemingly been spared, but otherwise they were lost.And then the mane six ccame tgoether, and the leements were reborn, and their form changed to match themThen when the elements were returned to the tree, the tre made a box. the box became a power for them to access agaisnt tirek, and the box itself became a castle, which thus created a map that the tree speaks through.I bet that if the tree were to die, it would simply take on another form. A form more suited to what needed to be done next, and to promote harmony.