OP isn't leaving details out in my opinion. She's quick to respond when it suits her narrative. She glossed over the rest, which is quite indicative of how she's dealing with this situation.
And when many of us (with non NT children, so have direct experience) have pointed out, that her DS won't be sitting quietly, but is likely trying to direct conversation with children that aren't interested and want to do their own thing (as they're entitled too), and he's done it long term, daily, which they've tolerated, and now, with him not taking any hint, their tolerance has worn thin, OP ignores these posts.
She only sees her son as a victim. As mine can be, he is most likely irritating these children, daily, in their only free time, and they are wanting to be left alone. OP needs to deal directly with her son. This "the others need to be inclusive" is a false charade. Being inclusive is not forcing children to eat with/play with someone they simply don't like, when there are plenty of alternatives. They're not bullying him, and teaching him that people essentially telling him "Enough!", is bullying, is a very dangerous game indeed. They are allowed no boundaries, and somehow he's entitled to annoy them everyday because he has SEN? Yes, I know he doesn't mean too. Neither does mine. Doesn't change the fact that he does, and it's not their fault either. This creating him to be a victim is not helping him.