Can beta-features be added to the app on the App Store? We are working on an iOS app which is already on the App Store. We are planning some new features for the app. Can we add these unfinished features in a beta mode? Will Apple allow this?
No Demos, Betas, or Trial Versions

From the App Store Review Guidelines …


  2.2 Beta Testing
  
  Demos, betas, and trial versions of your app don’t belong on the App Store – use TestFlight instead. 


Still unsure? Only Apple can answer this question authoritatively. Please contact Apple iTunes Connect team directly and ask.