The $40K appears to be a top line number. That's a foolish metric IMO. If a kid generates $40K in top line income by selling T shirts and traveling around for private appearances then he loses his scholarship. Yet the kid could very well have $20K in costs, so for $20K in actual profit the kid would lose his scholarship.
Also - How is this going to be verified? Tax returns? Will the NCAA begin reviewing income tax filings of scholarship athletes? Will they assume to have auditing authority? This is why I predict that a federal alphabet agency will eventually be given regulating authority over this new sub-industry.
Gonna be interesting to see this play out.