Will the CXU decode DTS Master Audio & Dolby TrueHD to enable a connection to a non-HDMI AV Receiver?

Yes, the CXU will fully decode both DTS HD Master Audio and Dolby TrueHD, and output these new HD audio CODECs (as well as legacy formats like Dolby Digital and DTS) via the analogue outputs, allowing connection to an older non-HDMI AV Receiver.

Additionally, if your older AVR does process HDMI audio but not the latest HD audio CODECs, the CXU can decode the latest CODECs and output them over HDMI as PCM, which will allow connection to an older version HDMI AV Receiver.