A:Answer Adding another Subwoofer to your 5.1 Home Theater System to make it a 5.2 Home Theater System does not change the common six-channel surround sound audio systems Dolby Digital, Dolby Pro Logic II, DTS, SDDS, and THX which are all common 5.1 systems. You're still transmitting a 5.1 surround sound signal that is being sent to two Subwoofers instead on the one Subwoofer system so it's not that the TV only supports 5.1 Home Theater Systems. We are not sure which 2019 model you are comparing to the LG NanoCell 85 Series 2020 65 inch Class 4K Smart UHD NanoCell TV w/ AI ThinQ® (64.5'' Diag), Model # 65NANO85UNA, but this TV features 2 x HDMI 2.1 ports and HDMI 3 is an HDMI eARC port. Dolby Atmos and even Dolby TrueHD lossless surround sound signals can be decoded by the TV and sent out (or passed through) over the eARC connector. The TV also supports the lossless Dolby TrueHD decoding format internally. Dolby TrueHD supports up to eight full-range channels (with room for expansion) of 24-bit/96 kHz audio (at the discretion of the studio) up to a maximum of 18 Mbps bitrate. You should still be able to use a 5.2 Home Theater System with our 2019 TV or the 2020 TVs since all you're doing is adding another Subwoofer to the system if it has two outputs to cater to the dual subwoofers. Both 5.1 and 5.2 setups are decoded by the same formats, and they support the same devices as well...^IFV