No. Its maintained and updated there.
Another question is why? You can sync with git or just download it from the page, identical to if you were to download it hosted elsewhere.
Splunk Java SDK is a public repo on github so you don't even need to create an account on github. The dev portal also has a direct link to the zip file - http://dev.splunk.com/view/java-sdk/SP-CAAAECN.