In fact, I’d go further and suggest that it would be great if they were to set up their own forum.
Manifold already has a highly active discord, where they can discuss all the manifold-specific issues. This did not prevent the EA Forum from discussing the topic, and I doubt it would be much different if Manifold had a proper forum instead of a discord.
This is annoying because many of these discussions rate high on controversy but low on importance for EA.
It might seem low on importance for EA to you, but I suspect some people who are upset about Manifest inviting right-wing people do not consider it low-importance.
FYI: Emile Torres is using they/them pronouns. I think you should edit your comment to use their preferred pronouns.