BMI for a Two-Year Old?

Today I went in for an appointment and met with a dietitian as part of it. They weighed me and weighed Aidan and got our heights etc. She told me Aidan is in the 40th %tile for height and the 80th %tile for weight. She then proceeded to tell me that this put him in the 90th percentile for his BMI. I was thinking it was a bit odd they were using BMI, but continued to listen. I guess the AAP and CDC has endorsed this starting at age 2, but let's remember that they also say that doctors should use further assessments to see if excess fat is actually a problem (per here).

She then continued to tell me that I should watch out for Aidan because he could be on track to become obese. I was very polite in the moment, but in my head I was thinking, Heck no, woman! My child is only two and he looks and seems very healthy. And I can see this kid's ribs! I'm always worried that he doesn't have enough meat on his bones. Plus, I believe in intuitive eating and that kids are expert intuitive eaters. Plus, he runs around allllll the time. Plus, his primary doctor thinks he's doing well so I'll take his word over yours. Yeah, I totally over-reacted in my head, but even now it's still sticking with me. I think it's wise that we make sure our kids develop healthy habits while they're young and we do have an obesity epidemic in the US.

It was a very interesting experience for me. It totally caught me off guard. Completely. I never think of him as an overweight or hefty toddler at all. I think we're going to switch him to skim or 1% milk now and try to be a bit more mindful and make sure we offer him a wide variety of foods, regular meal times etc.

Has anybody else had an experience like this?