"As we collaborated over puzzles played out on vintage machinery, my older daughter said, “People back then must have been incredibly creative to make something like this."
I don't know any 6 or 8 year olds that talk like that.
For example - my youngest recently had an abscessed tooth removed. He is 5 this year. The dental surgeon was astounded that he used the words nitrous-oxide and Novocain. The surgeon said things like giggle gas and sleepy juice, and the five year old dead pan corrected him.
Kids will say what they hear - outside of a disability/difference of that kind. If they hear short baby talk, they say short baby talk. If they hear larger words, in context, often, then they'll use those.
Either way, I enjoyed the post.
... they don't care. At all.