I'll probably make theme suggestions at a later date, but for now I have another thing that Civ VII should not repeat.
If we're keeping the Greece/Macedon split (which I... think I like), then please, Geoff Knorr- USE GREEK MUSIC. In Civ VI, Macedon uses North Macedonian (a Slavic country) music, which did absolutely nothing to help the nationalist naming dispute and actually convinced some people that the Macedon civ was claiming Alex was from North Macedonia.
In a supposed historical 4X, I see that as a cardinal sin so great we can never let that happen again.
So, instead of using unrelated Slavic music, why not use Greek Macedonian music? According to Knorr, the reason he chose North Macedonian music for Macedon's themes was because ancient Greek music was already represented in-game. Personally, I find that a flimsy excuse that does not justify something so ahistorical and controversial. Even if he didn't want to use ancient Greek music for Macedon, he could have at least used modern, anachronistic music for them. It wouldn't be anything unique when the OST already had Mo Li Hua for China and Arirang for Korea.
I even know a Macedonian Kalamatianos (an upbeat Greek dance in 7/8- Tino Mori's time signature) that fits Tino Mori's mood. It also wouldn't be hard to find a replacement for Buvcansko Oro, the dark middle section of Macedon's theme. I actually made an arrangement for Macedon's theme using my two authentic replacements for Macedon's songs, and as it turns out, you can do it while keeping the EXACT SAME mood as Macedon's actual theme. This means there was basically no reason to use North Macedonian music, because Greek Macedonian music could have fit just as well.
But, music geek rambling aside, my point is that if Civ ever tries to represent Macedon again, the composers need to make a music choice that will dispute the Macedonia naming dispute rather than fuel it.
(And, don't get me wrong- I love Macedon's theme in Civ VI and I'm so glad that I know Tino Mori and Buvcansko Oro. I find both of them extremely catchy melodies and find them endlessly replayable. I just don't think they should have been chosen for Macedon's theme.)