This is true that it primarily applies to jobs which say they need to know Japanese as an attempt to prevent fraud, but realistically it doesn't actually accomplish anything beyond punishing honest businesses. Companies will just lie about the language requirements, and visa holders will have no incentive to properly report the fraud because they run the risk of their visa being revoked and kicked out of the country.

There are smarter ways to implement a language requirement, and really this is part of a trend of Japan tightening up restrictions on foreigners to try and solve a perceived problem by a fraction of a fraction of individuals.