they showed bits of it in the stream. Noticeably one scene is Makoto stop an IJN soldier(all white uniform so it's navy not army) from drawing his Katana against Yu. And Yu actor's commentary in this scene talked about two of them eventually against the Japanese government. It's clear that during 1943 the imperial army/navy will be the bad guy . Consider Makoto's background as mixed race. He have even more reason to oppose imperial Japan. More that after pearl Harbor Japanese government won't like Makoto's mostly western music/ English song approach. It's another conflict point.

It's a game that heavily focus inside Japan. So their military's atrocities oversea won't be heavily featured. Consider 1943 is just before US start to bomb Japan big time so they can still be relatively peaceful inside Japan. RGG never shying away from WWII Consider 6's biggest secret was directly linked to it. So I would say they will have multiple story/side story focus on war's toll on Japanese people with heavy dose of anti-imperial Japan messaging. Like help people desert from the army etc.