I was thinking of a different explanation, but I suspect that the real reason is what @FrankCox wrote.
Still, I’ll share what my initial thought was. Namely, that the Japanese economy is all messed up and the yen-to-the-dollar is so out of whack, I was thinking maybe Yamaha was needing to raise its prices because of that. For example, the weak yen is beneficial when selling Japanese products abroad, but the yen’s buying power is limited because it’s so weak, such that something like a piano, which must use wood and other materials sourced outside of Japan, would be come increasingly expensive.
But yeah, I don’t think that’s the explanation here.