Joy,
I see the point you're making but what I'm assuming is:
INeed has a mobile and possibly a landline.
The DP can pick up the phone and ring his son, should he choose to do.
The DP can text to make access arrangements.
The DP can email to make access arrangements: She hasn't blocked him, she's just compartmentalised him.
I think if INeed came here and said that she was blocking communication between them, she'd be asked not to. So I'm wondering if we're reading the same thread?
Nowhere have I read that she is obstructing the two of them having a conversation or a meet up. What she is doing is trying get through a terrible time, both for herself and her son.
Of course, her son is utterly bewildered - his family life as he knew it has just radically changed, and change does not necessarily mean better or worse. It is not of his choosing - and that is a 'normal' breakup. The issue we all feel sorry about is the abrupt and cowardly way it was done.
It hurts everyone.
The OP could pretend everything was okay for two weeks. Indeed, Ineed and exDP could have sat down together, at at time convenient for exDP, when he has returned from his holiday to say 'Ma and Pa loves you, but Pa doesn't live here any more'.
So for two weeks his life has been a lie. He's old enough to get that.
She has also decided to tell him now, whilst she has the time free from work, and, critically, before he makes the big jump to secondary school.
I would say 'timing' is everything in this situation: the fact that he already had a big change coming up (a milestone), she is now having now has to manage the collapse of family life as well.
I think INeed realises that her son IS the most important factor here.
An apology won't even to begin to cover it. She's not looking for ideas to punish the DP, she's looking for ideas on how to cope. How to best support her child.
If the son was writing on MN, he'd be given advice accordingly. If the DP was, so would he.
There is nothing fair about her situation, or that of her son's. Clearly there are mistakes to be made, but the DP is a parent too, the onus is on him just as much as INeed to take care of the welfare needs of the child. The onus is very much on DP to make contact with his son.
To pretend otherwise, is to permit irresponsible parenting.