To put this in context, in the 2015 election, the opposition got 7.7 million votes (56%), Maduro’s party got 5.6 million (41%) and estimated turnout was 74% then. So it looks like this year they got a majority, but not a crushing victory.
https://en.m.wikipedia.org/wiki/Venezuelan_parliamentary_election,_2015
Violence and intimidation from the regime played a role in the vote with some not showing up out of fear, keeping the anti vote down some.