EBD teacher, learning to be prosocial involves being able to access the general knowledge of mainstream society too. Not knowing the basics of how the world operates outside of a narrow, often dysfunctional social context (parents in prison, DV, poverty) etc can be incredibly damaging. The common currency of everyday conversation involves a lot of facts - whether it's X factor or the Queen of England is not always relevant, but it can be. A lot of humour is very verbal and makes references to all sorts of topical info - this year a lot of it will be about the Diamond Jubilee. When students don't know and can't access these facts, they are excluded from conversations. This happens in lessons, too. You can't have a conversation without having something to say, and to have something to say, you have to have access to these facts.
I work with students who have severe language and communication problems and to be honest, I think a "skills based" curriculum absolutely does them no favours. I need them to become confident pro-social members of society too, but I have a recurring issue when it comes to various aspects of the curriculum and how they are asked to deploy "skills" when they don't have the basic fundamentals to allow them to retain the necessary knowledge to make those skills relevant or generalisable. I would far rather that the facts of history were used to enable them to have conversations about past and present and to think about how humans change over time than to demonstrate "skills" such as "plotting a timeline" without really understanding it in any way that is meaningful or relevant to them.
Wrt to the Speaking and Listening curriculum which is cross-curricular, there is a constant push to make them "talk for purpose" and "speak for an audience" and employ all these nonsensical "communication skills" ahead of having a basic bank of knowledge and capability to have a normal conversation on their own terms. Some of the kids I work with don't have basic vocabulary to describe ordering food in a restaurant, let alone do it independently.. and they need this knowledge in order to develop the skill of being able to interact in these social situations. Yet the "speaking and listening" experiences they access at school involve listening to peers reading aloud with volume/intonation etc, reading text they don't understand or engage with, they nod when they are told they are being assessed as they know this gets extra points. They don't have a clue what's being said, but hey, they know the reader should speak a bit louder because the teacher wrote that on the board. It makes me cringe.
Similarly, I see a lot of meaningless "social skills" stuff being done with kids with limited or impoverished language (which as you know, applies to 70% and upwards of the EBD population) when the gaps that they are experiencing really reflect limited language to describe or mediate experience. It doesn't make one whit of difference if you know that it is nice to greet people and to take turns in conversation if every time someone speaks to you, you haven't a notion what they are saying and then feel like you want to thump them yet don't even understand that you are responsible for that. I've recently done a lot of work with a young offender on what "by accident" really means. He thought that because he rarely went into a situation wanting to be violent that it wasn't his fault when he became violent, because his intentions were good at the outset. We established that he is often violent when he doesn't understand what people are talking about, or when conversation goes above him which he perceives as people "dissing him". There is no prosocial skill that will replace an increase in ability to understand general conversation and life and giving kids meaningful experiences and broadening their general knowledge base can be more important for many than talking about the "skills" you need in some abstract, meaningless way.