It’s probably explained wrong. ACF5 Pro is available for free for anyone that has purchased any of the premium addons in the past. To suggest that the wording be changed to make it more clear your best bet is to submit a new support ticket https://support.advancedcustomfields.com/new-ticket/
The developer is hard at work getting a free version of ACF5 released… and while I’m not going to tell you where, because I don’t like to promote such things, if you look hard enough you can find ACF5 Pro out in the wild to be downloaded. Seriously though, the reason I do not promote such things is that ACF Pro is likely the cheapest and best deal for any premium plugin in existence.
