While meta keywords have no value for Google or Bing rankings, they may still matter for some search engines.
We recognize that more SEOs and digital marketers concentrate their efforts on the dominating search engines. Yet, there are also experts who build strategies for more search engines to reach a bigger audience or primarily target geographies where the main search engine is not Google or Bing.
Accordingly, not to limit your opportunities in any way, we have not removed the meta keywords data from our On_Page API response. If you do not need this data, simply ignore the "meta_keywords" field and related checks.