In response to the OP, no.
Not sure why a mid 20th century pop producer has to be invoked in order to differentiate between orchestral and chamber music? The differences have been around for much longer than mid century pop.
From my view, as a fan of mid to late 20th century and contemporary classical music, the differences between chamber and orchestral music have seemed to blur a bit.
Chamber ensembles of larger size, and chamber orchestras are pretty popular among mid to late 20th century, and contemporary composes, and often with a combination of instruments unusual by 19th century standards. This can tend to give them more harmonic substance than more standard chamber ensembles (string quartets, piano trios)
And orchestral music, maybe due to increased complexity of late 20th century music (the various sections being more independent from each other), do not sound as ’lush and overblown’ as in the past, so they can tend to have some of the attributes of chamber ensembles.
Coincidently, I was listening to Elliott Carter’s, "Piano Concerto (1964)" last night, and thinking to myself, "this comes off more like a chamber piece, than orchestral". Maybe the independence of each section of the orchestra gives them more of the sort of role each individual instrument would have a chamber piece?
And, on the other hand, Charles Wuorinen’s "Concerto for flute and 10 players (1964)" seems to me, to have more ’weight’ than the number of musicians would have one believe for so few (by orchestral standards) musicians.