Is what my pediatrician said inappropriate?

My kids see a very respected pediatrician. He was very hard to obtain as a primary doctor because he’s so well desired. He’s been in practice for 35 years, teaches pediatrics at a medical school, and has tons of published medical articles. I’m always ecstatic with him because he explains things so well and is sooo good with my kids.

Anyway, today my child had a well-visit check up. I was mentioning my child seems to have a lot of separation anxiety. This is how the convo went:

Him: “Separation anxiety is a good thing at this age. It means he’s cognitively normal! You know who doesn’t experience separation anxiety? Kids with cognitive delays or things like Down syndrome.”

Me: “Oh really? I didn’t know that.”

Him: “Yes, so be grateful in a way that, in other words, your child isn’t slow. Down syndrome kids and slow kids in particular are always praised for being “good babies” that are always happy and don’t cry often, but that’s actually a bad thing. It means they don’t really understand what’s going on around them. Studies show that the more intelligent a child is, the more “difficult” they are as babies: crying, separation anxiety, etc.”

After that I didn’t really know what to say so I just said okay and changed the subject.

Do you think what he said was kind of offensive or inappropriate?