Except you'd want to sign it. It's not a petition to leave, it's a petition to stay.
The separatists were proposing a question "Do you agree that the province shall become a sovereign country and cease to be a province of Canada?" which would mean even if, for example, 2 million Albertans refused to sign it, it wouldn't matter if 177 thousand people agreed to do so. Under the new question, "Do you agree that Alberta should remain in Canada?" if those 2 million Albertans signed the petition, it wouldn't matter if those 177 thousand refused to sign it. Granted, it is a gamble because it's easier to do a thing rather than not do a thing.
I could be wrong on his intentions, but considering that Lukaszuk is the head of a movement called Forever Canadian, and from his twitter it seems like he's pro-Canada.
Edit: I meant it's easier to not do a thing rather than do a thing, wording got mixed up there.