Coming in late on this, but yes, I think the situation you described is abusive coaching. I think that when we allow our children to be mistreated and bullied by coaches, we are teaching them that it is okay. Like Dunno said, I think it will carry on to how they let others treat them as well, boyfriends/girlfriends, husbands/wives, friends, etc. I would rather my child NOT do gymnastics than leave her in a situation where the coach was bullying her. I still never understand why parents let their children be treated this way, it boggles my mind every time I hear a story about abusive/bullying type coaching, I just can't imagine leaving my child in the hands of someone who would yell at them, bully them, belittle them, etc. NO sport is worth that. Period.
I hope that your talk had an effect on the coach, but in my experience, coaches that treat kids that way will continue to do that. Sure, people can change, but I think it takes a lot more than a parent complaining for them to change. Sadly, as long as parents continue to allow these coaches to bully/mistreat their kids, it will still go on.