From memory, I believe that Elliot’s plan was always to release ACF5 to the WP Repo. So eventually, anyone that’s using ACF4 will be able to upgrade to ACF5 unless they are using one of the premium addons. If they are using one or more of the addons then they’d need to upgrade to ACF5 Pro.
But I could be wrong. Let me see if I can get Elliot’s attention and an official answer.
