Unity3d Multiplayer Android/iOS Game

Background

Having the client web application and the server on the same network is safer, as one can expose the server ports only within the network, instead of making them publicly available. I want to expose my Unity3D game using this safety measure and follow a DMZ approach.

Current State

Currently my game is compiled and build as a native application and shipped on the Android/iOS store. Users make requests over HTTPS to my (Server) REST Api. This opens up a whole bunch of security issues.

Goal

What I ultimately want is to have a small native application, essentially just a wrapper that loads my actual game from my remote Unity3D server. The Unity3D server communicates over internal network ports to my actual server and the database.

Question

Is it possible to expose Unity like this? The only way I have tested is compiling Unity as a WebGL project and embed it into a web server/framework like NodeJS, Angular or alike.