It's hard to say, depending on how far back your idea of "a few years ago" might be or where exactly you ate. After all, Japan has a lot of sushi restaurants and even different sushi styles. For example, you definitely wouldn't find salmon in an edomae sushi restaurant.

For reference, salmon was the most popular choice in conveyor belt sushi places 3 years ago. https://www.nippon.com/en/japan-data/h01627/