When migrating assets through X-Org 2.0, Horizon rule folders are not considered, and the migrated rule will be placed in the "uncategorized" folder by default, even if a rule folder with the same name is present.
It will be good idea if we can consider folders as well while migrating Horizon rules to reduce manual efforts to move it to particular folder in target org.
However, if a report located in a folder is migrated, it will be placed within the report folder, or if a folder with the same name/id does not exist in the target tenant, a new folder with the same name will be created. I would expect parody between these two assets folder migrations.