My IP can be seen by a Whatsapp contact using the netstat command. Can a VPN hide my real IP to them? Or their netstat will still show my real IP?
When messaging, WhatsApp contacts cannot see your IP address. WhatsApp itself can, of course. When making VoIP calls using WhatsApp, your IP might be visible to the contact.
Yes, you could in theory hide this using a VPN. You just have to ensure your VPN is configured correctly, and all internet communication on your phone is relayed through the VPN (before installing WhatsApp).