https://www.avsforum.com/wordpress/denon-introduces-2020-x-series-avrs/
Shared New Features
‧ 8K & HDMI 2.1
‧ Dolby Atmos Height Virtualization
‧ VRR (variable refresh rate) support
‧ Main Zone HDMI/TV Audio distribution to zone 2 or HEOS speakers
‧ Quick/Smart Selects store all zone stereo settings
‧ Bluetooth transmission to headphones
‧ HDMI Custom Input Assign
‧ HDMI Input Auto Rename
‧ AirPlay Disable
‧ Roon Tested
The new models are the Denon AVR-X6700H ($2499), AVR-X4700H ($1699),
AVR-X3700H ($1199), and AVR-X2700H ($849 MSRP). Denon also plans an HDMI
board upgrade to 2.1 for current AVR-X8500H owners.