I too accepted this limitation when I purchased the 975 - however my needs have changed over time.

I don't think you can infer much from the remote picture. The 975 remote has 7 device buttons (plus tuner). However the 975 only has 5 logical inputs and 4 HDMI inputs. The 976 remote picture has eight device buttons (plus tuner) and 6 HDMI ports. So one more button and two more HDMI port. Also the BT button might be specific to the bluetooth module (see upper left of rear view). As you say we need to wait an see once it is released.

Since I plan to use only 4 HDMI ports, I should be fine with the 976 even if the 976 has only 'number of logical inputs = number of HDMI ports'. I am planning to get a 976 - I do't need ATMOS but I am planning to get a 4K TV within a year or so.

Just getting a new TV might also solve my problem if it has Amazon Video built in. Then I can get rid of my Fire TV and so free up another input.