Just a hunch but if the Spurs draft Kai Jones, he may not be the long-term Austin project we all are assuming.
The initial training he receives will likely be from Pop and potentially Duncan -- Duncan is an island guy like Kai and came to basketball relatively late, like Kai. He could be a mentor in all senses of the word.
In addition, Austin doesn't seem like the kind of place where big men go to learn the game, more like wings and potential playmakers. While Kai might play some games in Austin, he might also be on the floor with the big team fairly early on, perhaps earlier than we think.