Yea, unfortunately DID is misunderstood for a variety of reasons including to a degree topics like Cybil and the psychological profession in many ways. (which is improving to a degree with a bit more research and understanding).
I can to a degree relate the that which is classified as inappropriate laughter, as I was diagnosed with that as well before I turned 21 or maybe it was after, I have some rather fuzzy memories because of my own situation, a lot of self-medicating a destructive behaviors I am thankfully not repeating (at least one is a vice still that I am not at a point yet to release and that is tobacco use.)
I hopefully am at a turning point which will allow me to deep dive my traumas and can work through that because tobacco is inter connected to one of early traumas as it was a grooming tool.
I can't imagine ever telling my children about DID. I haven't even told my husband, though I have explained it in vague terms. The label scares me and I am afraid it will scare him. He's had to put up with so much.
Yeah, this is me and my relationship with work and my management (everyone from Food on down to the Deli Department) who know I have disabilities, yet they don't know and don't recognize that when they are dealing with me, they don't know who they are really dealing with depending on the moment of interaction.
He's probably resilient as some children are and maybe won't have the issues you fear, if possible, maybe having him talk to a professional may not be a bad thing. (just a thought here) I know that mom being mom, From a son's point of view, is my mom caring and worrying about her little boy who is now 45 in my case and that sometimes it's her seeing me as her little boy and not in the adult perspective.
Sean/Geordie