“Not you or me, that�s for sure.”
So if the Moetzes Gedolei HaTorah decide to make a Torah world event (Siyum, Asifa, rabbinic meeting, protest or whatever else) unifying the various segments, kehilas and communities in Klal Yisroel including Litvish, Chasidish and Sefardic, but there’s no official MO leadership participation or invitation, then we can presumably assume the Tzadikim on the Moetzes made an informed decision resulting in the inclusion that was selected.