Ionic app developers faced challenges with app submissions to the iOS App Store due to the use of a private API by the Ionic Keyboard plugin, which led to rejections for "non-public API use." The issue stemmed from the hideKeyboardAccessoryBar method, which was employed to make the keyboard resemble a native one by removing the accessory bar. Developers are assured that their apps already in the App Store are not at risk, and the plugin has been updated to remove the problematic method. Despite the lack of a public API to remove the accessory bar, Ionic is exploring future solutions that won't risk App Store compliance. The team is committed to keeping developers informed and updated on any developments regarding this issue.