Just getting back into CoH3, what should I know?

So I bought the game at launch and played a bit but then quit until now. What should I know for multiple that's changed? What balance things should I know?

For reference last I played I remembered the Italian flamer guys and Italian flamer light tanks were OP (I'm mostly playing DAK again).

Also I remember that the Aussies and archer tank were hidden in the files at launch. Why did they only release like 6 months ago? It's weird. Also were they always in the campaign? Or were they added recently?