Not exactly...using MD/CD-R out would be like plugging the source player directly into the pre-amp...the volume (gain) has no impact on this output.
Pre-outs do respond to the volume, so you can connect the receiver directly to an amp.

I do think you could connect the receiver to an integrated or pre-amp through the MD/CD-R outs however, sort of like splicing the source player signal to two different components. Never really though of this kind of setup before.