Basically it was to give somewhat of a blue print for peace after ww1
<h2>Answer:</h2><h2>key is yawi kaloha sa Susi </h2><h2>Explanation:</h2><h2>ohh and happy kana</h2>
But in modern times, as we see, Wakanda is a thriving, flourishing civilization with few conflicts with the outside world. So the primary function of challenge day is keeping the peace internally, with making sure the Black Panther is a fit protector now a secondary outcome. And there for it was kept a hidden for a while.