AI-mediated deliberation also reduced division within groups, with participants’ reported stances converging toward a common position on the issue after deliberation; this result did not occur when discussants directly exchanged views, unmediated. Although support for the majority position increased after deliberation, the Habermas Machine demonstrably incorporated minority critiques into revised statements.
Personal opinion based on experience follows.
Ok, so what AI did was offer a 3rd party perspective that was not seen as biased by the participants and made sure to include everyone. The AI served as a competent facilitator to the process.
This can be done by human facilitators, although there is often and assumption that a human will have bias when someone's important detail isn't included while a non-human doing the same task would be assumed to he neutral.
So in short, the AI did something that a human can do, but by having AI complete the steps it reduced the audiences perception of the process and that impacted the oucome. The main outcome is that AI is a benefit in this context, not because of how it summarized, but because it did the summarizing.
I normally criticize AI for being jammed into places it doesn't belong, especially without any review of its output, but this is a great use of AI. It does the complex stuff and gets reviewed, and the perception of neutrality is a benefit to the process.