Increased turnout is likely to be helpful for the NDP and not for the Conservatives. Older voters, who are more likely to vote Conservative, already have a high turnout. Increases are most likely to come from younger cohorts who are much less inclined to support the Conservatives.
Look at the difference, for example, between the Under 25s and Over 65s from Friday's Ekos poll:
I suspect all the youth voting turnout initiatives, the vote mobs and so on, are probably making Mr. Harper nervous.