Android P will block apps from monitoring your network activity
Android privacy vulnerabilities exposed more than a year ago have finally been repaired. At present, the Android-based APP can obtain complete network link function without consulting any sensitive new brand. Although these APPs cannot detect the content of a network call, they can use TCP/UDP to sniff incoming and outgoing connections to determine if you are connected to a particular server. For example, an application can detect whether other applications in the device are connected to the financial institution’s server.
However, Android’s SELinux rules have adjusted it, and access to certain information is limited. In Android P, SELinux rules only allow specified VPN applications to access some files. Other applications for access to the APP will be reviewed by the system. For compatibility purposes, those API levels less than 28 can still access these files. This means that most applications still get this file.
Source, Image: xda-developers