No, they simply ran on a platform that they'd have a referendum.
The story in Ontario—and I'm quite sure in British Columbia—is that the parties didn't take positions on it. In fact, if you read the media, you would have found it hard to know that when you went to vote you would have two ballots: one for whom to vote for, and one on the referendum. Indeed, 138,000 fewer ballots were cast on the referendum question in Ontario. They were left blank.