I'm not sure of my own position, but I think the fundamental moral difference for those supporting moderation is that if one does have the ability to moderate,

I'm not sure of my own position, but I think the fundamental moral difference for those supporting moderation is that if one does have the ability to moderate, then they should have a moral obligation to do so. Technically, there's no central authority that can moderate Signal, so you can't have the moral obligation there. I don't think there would be a significant proportion of people that would advocate for Signal to become centralized so it would allow moderation by a central authority. Another perhaps more cynical take is that even if there is hate-speech and other undesirable communication in Signal, it's not seen so people aren't concerned about it. As they say, "out of sight, out of mind." That makes me wonder if expectations would change if people started publishing screenshots of Signal groups with hate-speech. I think they'd be pretty limited to small sizes, so perhaps they wouldn't be as concerning.