You are not tied to stay in AB after you get your PR. It's mainly the question of landing there and staying a couple of months after that, then you can start thinking about a move. I've heard the 3 year rumour before but it's just that, a rumour. There is no truth to it whatsoever. As a Canadian PR, according to the charter of rights and freedoms, you have the right to live and work in any province. Check out the job market though before you move. If there's not much on the job front where you are, you don't want to move somewhere where it's worse.