No one should force people to live in a place with X politics, so yes it's entirely possible most of those places would be almost empty or not exist at all. No manipulation performed to make people stay. The balance of how many resources should be given to these societies can be determined by the ASI as it observes and talks with people. Though likely a radical abundance of resources will make this a non-issue for sustaining less technological societies.

People with a very niche ideal society would have to live with the fact that no one else wants to live there with them. If there are not enough residents to make that niche society function as the human would prefer, then the oddball would need to either try to integrate into whatever is available, or go live in VR land with virtual residents of their favorite society. However, if enough people existed in total, then the chance of this society existing would be higher.

Eventually, people would independently sort themselves so that they spend most of their time in whichever most ideal population clusters exist, without being forced to do anything.