Almost a year ago ( in may) samsung promised to all the reviewer of their product that they would release a eARC version firmware update, months later the new 2020 line up integrate eARC (to be verify) but still no words of the eARC firmware of the 2019 lineup:
https://www.reddit.com/r/Soundbars/comments/dz0ihk/samsung_hwq90r_earc_q80r_and_q70r_firmware_update/
https://eu.community.samsung.com/t5/Audio-Video/What-is-going-on-with-eARC-update-for-the-soundbar-HW-Q90R/td-p/1368639/page/39
https://twitter.com/SamsungSupport/status/1216006640622657536
For all the burnt ones like me, raise your voice on twitter #earcSamsungGate
This behavior could help you in your choice for a brand of your new homethetaer
