In Swimlane view, you can now reorder lanes by dragging a lane heading or by using the left and right buttons that appear when you hover over a heading.
For processes where you have edit permission, the new order is saved as the Assignment labels order. For processes where you only have view permission, only the on-screen display order changes, and it reverts when you Reload the page.
Related: Reordering lanes in a Swimlane
https://teachme.jp/8/manuals/50824522