I’ve never wondered why Japanese shochu is also labeled as soju in the U.S. I didn’t care much about the issue ever, it turned out that it is necessary to know the inside track as long as there is special reason.
Here is the answer.
The liquor licensing laws in the states of California and New York classify soju in the same category as beer and wine, allowing businesses with a beer/wine license to sell it without requiring the more expensive license required for other distilled spirits. The only codicil is that the soju must be clearly labelled as such and contain less than 25% alcohol.
This has led to the appearance in the United States of many soju-based equivalents of traditional Western mixed drinks normally based on vodka or similar spirits, such as the soju martini and the soju cosmopolitan. Another consequence is that the manufacturers of similar distilled spirits from other parts of Asia, such as Japanese shochu, have begun to relabel their products as soju for sale in those regions. quoting from Wikipedia
So, that means it is better to make them labelled as Soju.
However, there are some Japanese brands represented like 'Yokaichi' labeled as shochu that has been produced by the company which gives priority to the policy than the cost even in the U.S.