About a year ago, Google announced its plans to deprecate the Google Earth APITrack this API. When Google originally announced the deprecation, the API was scheduled to be taken down on December 15, 2015. However, the Google Earth team recently communicated to the Google Earth Blog the intention to keep the API up and running for a bit longer. While an exact date was not provided, the Google Earth Blog reported that the API should remain available at least through the end of this year.
While the temporary extension does breathe a little more life into the popular API, developers should continue to make a transition plan. Lack of popularity or use was not the problem with the Google Earth API. Rather, the API is based on legacy NPAPI technology that has known security issues and continues to lose cross-platform support. Accordingly, don't expect the extension to perpetuate for any significant amount of time.
Although the Google Earth API remains on its way out, Google remains dedicated to continued support for Google Earth desktop and mobile applications. On the mobile side, Google will continue to develop Google Earth for Android. The API deprecation seems driven by the legacy technology issues, as opposed to the application itself.