I am currently using ACF v4 with the following addons: Repeater, Gallery, Flexible Content, and Options page. I have some bidirectional fields that are not yet compatible with v5. I would like to know how long I will be able to run the v4 plugins and addons before being forced to upgrade to v5?
A new free version is currently in the works for V5. I assume that once the V5 version is released to the plugin repo that will be it. The new version is currently in Beta https://www.advancedcustomfields.com/blog/acf-5-early-access/
At one time the developer said he wanted to release this new version to the WP Repo by the end of the year.
You might want to test it out.