I’m not convinced of that, the stone tools (projectile points) found during that period were to large for bow’s but normal for an Atlatl.
In 1911 Ishi (Last of the Yahi tribe in California) turned himself in and was befriended by Saxton Pope. His knowledge of archery was an interest to Dr. Pope, Ishi was making his own bows/arrows from local tree’s and his projectile points were made of stone and what glass he could salvage from local settlements.