Hello,
I do not expect top quality and low quality items decrease, but medium range has decrease and could continue in that trend
However, it also depend of economical and political environment. I understand that president elected Trump would like to re-establish border barriers and set up tax to imports.
If so and if nihonto would be concerned, that would make imports from Japan more expensive and influence the market trend on both US and Japan. Of course, also depending of the exchange rate Yen-dollars.