I believe that having a Creative Cloud subscription or InDesign subscription is required for using Publish Online. There may be a "grace period" where it still works after you've left your subscription, but I've never seen any published information that guarantees this.
Thanks Steve. That's a bit disappointing.
As per your query is concerned, let me inform you that the links for "Published Documents" will remain active even after the subscription is ended. There is no time frame to disable them as of now, however Adobe will have the right to remove them in future if there is a need.