TPM: Every time I get into a discussion with a person regarding the curve and kids, I first define what we are talking about. It is very rare to see an 11 year old be able to throw a proper curve and have it be effective on the small diamond. The reasons are twofold. First there is not enough distance for the ball to break downwards and second at that age they cannot get enough rotational velocity due to immaturity.
The opening question I ask is what is the rotation of the pitch we are talking about? When I watch one of these touted kids it is invariably rotating at about 45 degrees. That pitch, the slurve or LL curve, does indeed stress the elbow.
Like you, I doubt the velocities quoted in this portion of the string unless the kid is an early physical bloomer. Like you, I believe the problem is overuse. In fact, I will state that if the kids were playing less than 40 games per season and only playing twice a week they could throw with the worst technique possible and not hurt their arms.
It is sad that this story is repeated in many places every year, more in warm climates. But, as I said ad nauseum, it is impossible to protect a child from his parents.
Finally, remember that education is the solution only to the degree that ignorance is the problem. So long as parents keep drinking the Kool Aid and ambitious coaches keep shoveling the ****, there will continue to be damaged kids like we are talking about. And the curve is not the culprit if thrown properly. That is a huge caveat. Kids do not throw enough to strengthen their arms but they pitch way too much.