Yeah, I can see where you'd wonder after reading the (lengthy) notes,
but the last 4 tracks are from that Dial 6 along with the Bartók from Dial 1.
You'll notice that the Khatchaturian and Bartók are from an RCA 78 and
the Avakian announcement and the two sections from "Lousadzak" are
from the Carnegie Hall concert of '47 that was only available on V-Disc.
Nagoski manages to do a good job on these restorations.
(and yes, the Messiaen is from Dial 8 which you can read
about its history and reception in those notes too).