I'd lean towards older parents being more proactive as to the reason behind the statistics. I had my two older kids in my twenties and my last in my thirties. In my twenties, the teacher and principal were still "authority figures" to me, and I often accepted their decisions because they were in authority. As a mom in my in my forties now, I am very clear when I am in a meeting that I am the mom, and that makes my decision the one that bears the most importance - not the teacher's or principal's. Not that I don't respect their point of view or expertise, but I'm not intimidated the way I was as a young mom. Had I been a young mom with my last kid, I doubt he'd be identified as 2e. I wouldn't take no for an answer and didn't accept the head-patting this time, and I pushed for testing until the school finally acquiesced - in part, I'm sure, to make me go away.
So from my own myopic personal experience, I know my son's identification is completely related to my own age.
