What would the great Fumblemort do with all that time on his hands? Likely as not, sit on his ass and do exactly what he's done since that moronic prophecy was spoken. Absolutely fucking NOTHING USEFUL!! He had all those years since it was first spoken to find out how Voldy stayed on this plane but never bothered to do more then find out how. So why would anyone expect him to finally get off his bony old ass now?! He's a glory hound and has gotten two students and one teacher killed needlessly. So ask yourself this, how many needless deaths is he responsible for in the first war with Riddle?