The Finder does not say the file is containing compressed data.
AIFF-C does not mean the file is compressed. This is a newer and more universal format that handles both compressed an uncompressed format. WaveLab does not compress audio in this AIFF-C.
Sorry, I thought this was the old AIFC problem where some programs wouldn’t play the files. Seems nearly all new AIFF files from most programs, like iTunes, are identified by Mac OS as AIFF-C now.