MAL Updater OS X 2.3.14 is now released and is the final release for macOS Mavericks and Yosemite. It backports some of the fixes and improvements from 2.4 and adds input validation to prevent improper scrobbles such as scrobbling a show that haven’t been aired yet. The legacy branch will receive detection updates until February 2019.
MAL Updater OS X 2.4 Beta 6 is now released and might be the final beta release before the full release late next week. This release have some improvements and fixes. If there are not any major bugs, it will be slated for release on February 23, 2018. 2.4 will require macOS El Capitan or later.
To update to these releases, simply check for updates.