That link is comparing average numbers of NCAA D-I & EYBL.
I am also saying EYBL performance can be a good predictor of college performance. Now, don't take that to mean what it doesn't. It does NOT mean "player averaged x points in EYBL, so he should average X-y in college".
Much like certain projection models when looking at college to pro, it's an art. There are certain key stats and relationships between the stats, the team they're on, the teams they have played, physical attributes, etc.
But in the end - yes, there is predictive value in EYBL stats when projecting how a player will perform in college. The value comes from an analysis far deeper than looking at the stat sheet.