User blog comment:Brandon Rhea/How we're testing the fandom.com domain migration/@comment-24361909-20180930135247/@comment-20644-20181001183723

Do you mean moving from a structure like es.starwars.wikia.com to starwars.fandom.com/es? If so, it will initially only affect the international communities in the 3,200, but by early 2019 all communities with a language code in the URL will move to that structure.