I have suggested a certain book on here many times before.
It was recommended reading after I went through my divorce.
I can't speak to why a judge would make a decision they made, but I have to tell you that my ex husband called obsessively and it was horrible. He even called the police if I didn't answer the phone and had them do a "safety check". It was ridiculous. He basically demanded phone access to my son at any time day or night and the judge put a stop to it.
It was a little thing called a restraining order.
Plus, we had scheduled nights and times for my ex husband to call. That way, we could actually have some kind of life and my son could look forward to the call nights.
Every time my son was with his dad, I didn't call to say hello once a day or even at all during a weekend. It's not that I didn't miss my son, but my son was just fine not hearing my voice every single day. I didn't for one second think it was as though he was going to forget me or anything. I encouraged him to have a great time with his dad and told him I would be fine and ready and waiting when he got home.
For one thing, his dad calling so much was making my son so upset and worried that his dad couldn't "live" without him, that my son started having issues. It got to a point where my son felt that he was responsible for his dad's feelings and that's a lot of weight on a little kids shoulders.
You want to avoid that at all costs.
A therapist recommended that my ex husband and I read a book, out loud with our son during each of our time together. My ex husband refused to read it.
The sad thing is that it is just as beneficial to the parents, if not more, than for the kids.
My ex husband didn't want to get the message so a judge had to help him get it a different way.
This is just what happened in MY case so I only offer it up as a different perspective.
No matter what, you cannot say anything disparaging about your son's mother.
He is part you and part her. If you put her down in any way, then he may think there must be something wrong with him as well.
Also, little kids are really prone to blaming themselves for things and you don't want that to happen either.
What worked well for me was saying things like, "We're going to try things this way for a while and we'll see how it works out."
No emotion, no blame, no interjecting that it's a good thing or a bad thing or that it's forever....
Anyway, the book is called, "My Life Turned Upside Down But I Turned It Rightside Up" by Mary B. Field.
I highly recommend that you read it for yourself if nothing else.
My son is 16. I left his dad 15 years ago. I've been a single mom since.
Believe me, the more you are seemingly okay with the many changes that will likely come in the years ahead, the more equipped your son will be to handle them well too.
Ironically, my ex husband and I get along really pretty well now. It took a long time, but my son is too old and too big for us to haggle over things like phone calls. He communicates at will with each of his parents. We switch days if something special comes up.
Unless your ex has documented "emotional" problems, you will just be stirring dirt if you bring it up only in response to not being able to call your son every night.
Read the book I suggested.
Remember that your son is a child of divorce, but that doesn't make him "broken". He can have two parents and two houses and different ways of doing things at each place and still turn out just fine.
Those are the things he needs to be able to say to himself and believe.
It starts with his parents.
Best wishes.