As far as we can tell, the answer is yes. Obviously, it isn’t possible to poll the people of North Korea the way we can poll the people of South Korea. The best we can get is interviews with North Korean defectors and with North Korean citizens living in China. It’s probably not the most representative sample, of course, but support for reunification is very high among this group. See, for instance, this survey of 100 North Koreans living in China. While their reasons varied, 95 of them considered reunification “very necessary.”