The beta 5 demo is... the beta 5 demo. Like that's it.
The Steam launch started with Beta 6 which eventually was widely accepted as being renamed to Early Access 1, starting the Steam early access version of Ravenfield. Early Access 11 just released about a month ago, so in total there have been 11 big releases on Steam on top of itch.io's original 5 demo updates. So I guess EA11 is Beta 16? There's a roadmap on the Steam version that shows we're pretty close to a full release/leaving early access at this point.