I don't think the phrase 'Necro' has to be thought of as a bad thing here, or ever for that matter. Its simply what happened, not judging the act. That comes with whatever else an individual says in their post calling it a necro. And it IS still the most accurate description since this was in fact a previously dead thread that has been brought back to life....Or I suppose we could refer to this as reincarnating the thread?
I personally love it when it happens =) I get a kick out of reading something, thinking its new for a minute, and then feeling goofy when I realize its been on this site longer than I have. >.<