I feel like the infantry mode would massively benefit from thematic intro music (and background music) especially given that it’s faction vs faction with set weapons and vehicles.
The introductions to matches are often silent and really lacking in ambiance, the in-game announcer is really bland too, especially for the Russians. The in-game sound is mostly dominated by artillery and explosions, with some engines and gunfire in-between but would again benefit from some background music, maybe when capping or coming close to the end of the match.
One game that did this perfectly was the original MW2, these themes were incredible (as were WaW’s), see below.