I've been through both ways; desperately in need to talk to the ex and hoping that the ex would never talk to me anymore.
My first time break up experience was not a good one. It took me about 4 years to finally move on. Probably because he was my first love (euww. hee). I've felt lonely, miserable, on and off for that 4 years. At one time, I thought that I was doing fine, but the moment I heard something related to him, I'm falling apart.
That 4 years, I still talk to him, my ex. Not exactly everyday but still checking up on him. And, on that time, I still had this tiny hopes in me that someday we'd find our way back together or perhaps he would regret his act of taking me for granted. Hahaha.
I talked to him when I missed him a lot, I talked to him when I felt lonely, I talked to him even though he's with someone new on that time, I talked to him feeling that he was the one for me, and that I would never be able to love again. (Seriously, is this me? Haha)
Time passed and I've moved on; then only I can think and reflect on my actions. Yup, you should stop talking to your ex. It's over and as hard as it will be, you need to stop any connection with your ex, especially the first few months of post break up. You will only hurt yourself more.
The next break up experience, it was the other way round. I'm not talking to my ex at all, but I'm hoping that he would never talk to me. Yes, I know it sounded harsh but it's for the best. I will never be able to talk/ treat him the same way that I used to be, so talking to me after the break up would only hurt him more.
Don't talk to me when you missed me, don't talk to me when you feel lonely, don't talk to me when I've moved on, don't talk to me just because you feel like I'm the one for you and that you will never be able to love again.
I've moved one. This second break up experience was way different than the first one. I'm making space for my own self.
Things happen for reasons. Don't let your emotions clouding your judgement.