I spoke to someone on reddit who owns it and apparently it does do HDR!I have only really checked via Google. That suggests it didn't support HDR when released 8 years ago (was HDR a big thing back then?), but does now support it via a firmware update (at least HDR10 if not HDR10+).
I cannot easily find anything via the Denon site. Might be worth contacting them directly to clarify.