Japan has avoided the madness of tariffs and trade wars that has affected the west recently. Instead they have been quietly negotiating trade deals with everyone and generally getting along. Good on them! Also it includes cheese, which will make westerners in Japan very happy.
As a German living in Japan for the past four months I somewhat doubt that's going to change a lot. Maybe some lower prices in speciality stores, but I can't imagine my local supermarkets to stock more different cheese or that demand is rising just because a small piece of Camembert costs still expensive 3€ instead of 4€ (roughly converted from ¥), which I buy for 50 Cents in Germany.
The prices are also so high, because it's an exotic food with no use in the local cousine, meaning low demand.