First of all congratulations on completing nine years as an ISCian! It would be good to see some contributions from you now and then, if not on a regular basis.
Regarding your AdSense query - yes, once you republish an article, the AdSense earnings-association will automatically get extended, starting from the new date. In case you do return with consistent contributions, you can also request the Webmasters through a personal message to extend the AdSense association to another year. The Webmasters do this, even giving two or more years to those making quality contributions on a regular basis.
It is also a good idea to rewrite and resubmit some topic on which you had written earlier which was getting some traffic but was not getting earnings. You need not republish it. Instead, work on it anew. A new look article with a new perspective, more in-depth and informative to grab the readers' attention will be good for both, ISC and you. The earlier article can then be shifted to the archives and kept away from search engines, with the new one getting exposure on being approved for search engines to catch.
When you make a commitment, you create hope. When you keep a commitment you create trust! ~ John C. Maxwell