Yes, if you are planning to convert your native app to a webview-based app, it is essential to update your app policies to inform users about this change. In the updated policies, you should outline the reasons for transitioning to a webview-based app, any potential impacts on user experience, and how you plan to ensure the security and performance of the webview implementation. It's important to communicate these changes clearly to your users to maintain transparency and trust. Additionally, you should ensure that the policies comply with relevant security guidelines and regulations to safeguard user data and privacy within the webview environment.

Both the App Store and Google Play Store have specific guidelines and policies regarding app updates and user communication. When transitioning from a native app to a webview-based app, it's important to review the App Store and Google Play Store guidelines to understand their requirements for informing users about such changes.

In general, major changes to an app, such as a shift from native to webview-based functionality, often require an update to the app's privacy policy and user agreements. App Store and Google Play Store typically require clear and transparent communication with users regarding any significant changes that may impact their experience or privacy. Failure to comply with these guidelines could lead to rejection of app updates or potential removal from the app stores.

Therefore, it is advisable to thoroughly review the official guidelines provided by the App Store and Google Play Store and update your policies accordingly to ensure compliance with their requirements.