Being that eARC is part of the HDMI 2.1 specification and the 976 is version 2.0b I would not expect the 976 to support eARC. Since the 976 was already being marketed by the time HDMI 2.1 was even announced in late 2017 there is no expectation that it can or will support eARC. Possibly the Phoenix processor will but it is also well under development. eARC will be great if you do over the air or stream through your TV but for older equipment the older versions work pretty well.
_________________________
Music system
Model 990/7500/Magnepan 1.6 QRs/Technics SL1200 MK2/Aperion S-12 Subwoofer/OWA3/Sony NS75H DVD
APC H15 Power Conditioner

TV System
Large Advent Loudspeakers/ Polk center/Monoprice surrounds/Panasonic Viera 42 inch/Onkyo HT-RC260/Sony BDP S590/Directv


Home Theater System
Onkyo PR-SC886/Outlaw 7125 Klipsch RF-82 L/R,RC-62 center, RB-35 SR/SL, BENQ HT1075, Outlaw LFM1-EX/OPPO BDP-83/Directv
Harmony ONE
Blue Jeans and Monoprice interconnects
APC H15 Power Conditioner