Nope. That's not how it works. An app installed with permission to open a port can't open that port until you run the app. That alone proves you wrong.
That proves you either cannot read, nor think. The original post is complaining about an OPEN PORT you doofus, which means the app HAS BEEN RUN. I'm not saying anything about the app before it is run, I am talking about where there is OPEN PORT there is a security risk.
Also, the app will shut the port when the app is closed.
What is really funny here is that it just goes even further to prove what I was saying, that an open port on Android is a security risk. What you are saying is that that there cannot be an open port without an app behind it which means 100% of the time an open port on Android is a security risk.
Which is what I said.
So thanks for the support, even if you don't understand why it went that way.
The other way is to leave a connection open permanently. This uses more resources and data than an open port.
Innocent question - why would a malicious app care about using more resources and data?