my receiver is capable of detecting AAC streams
Yeah... I would have thought your drivers (or software) would just decode it... I've played MP3 files via HDMI into a TV (from Winamp) and I never even thought about it not working, although I wouldn't expect the TV to decode MP3. I assume you have a Windows computer or a Mac? I am using WindowsQuotemy receiver is capable of detecting AAC streamsAre you sure? ...If it has a USB port, it may only play AAC files from there.
HDMI 2.0 is capable of transmitting AAC
Features66AK2G02 C66x DSP+ARM A15 Processor at 600MHz2-GByte DDR3L with ECCTPS659118 PMICAudio and Serial expansion headersProcessor SDK Linux and TI-RTOS supportSupports Gigabit Ethernet
A couple of hours earlier, you got a reply that pointed out that although the Wikipedia article claims so, there is no support for the claim in its sources. No mention here: https://www.hdmi.org/manufacturer/hdmi_2_0/hdmi_2_0_faq.aspx
In Wikipedia they have mentioned under Version 2.0 it can support HE-AAC