The VPN (WiFi Privacy) should be included with the 5 or 10+ subscription; especially since the feature Call & Text Blocker is not supported on Android 4.4 or later and I have a very cheap cell phone considering what most pay and I'm on Android 7.1.1 with Samsung testing a version 8.5 Android, This feature you offer is pointless, give your customers some value!
The VPN product is not included because there are extra fees involved in providing that service. Not all users of Norton Mobile Security would want or need a VPN, so they would not want to have to pay for a service they will never use.
It is only the text blocking that is not available in Android 4.4 and later. Calls can still be blocked.