I did a quick search on the X2700H and found this for bitstream format:
Dolby Digital / DTS / Dolby Atmos / Dolby TrueHD / Dolby Digital Plus / DTS:X / DTS-HD Master Audio / DTS-HD High Resolution Audio / DTS Express
This would be similar to my Sony AVR and my previous Onko. AAC is rarely supported on the HDMI bitstream. Usually you have to convert to LPCM between 32kHz and 192kHz.
EDIT - I did a bit of further digging. The USB and network interfaces will support AAC "The Denon AVR-X2700H supports the following audio formats, sampling frequencies, and bit rates via its wired network connection." My Sony is similar on the USB interface, but not on the HDMI interface which is how your sat/terrestrial receiver is interfacing, so we are both right. On the sat box you will have to downmix AAC to PCM .