Given the recent article about how a website was using a zero volume audio signal to fingerprint browsers it's probably good to assume that "they" are trying to get you any way "they" can.

https://hackaday.com/2023/01/04/all-about-usb-c-resistors-and-emarkers/

There's a profit motive and a possible technological path. It's a safe assumption someone will eventually do it. That doesn't count bluetooth and wifi that only talks to other BrandX devices looking for a path out, and once 6G cell service becomes common it can be direct-to-device unless you're in a Faraday cage.

LG lost some trust after a recent report that some of its monitors installed McAfee pop-up ads onto connected computers. Since at least 2024, some of these displays installed an app, LG Monitor App Installer, onto connected computers under the cover of driver updates installed through Windows Update.

Connecting the monitor to the computer triggers a Windows driver update. LG grabs that update request and returns an app that automatically installs itself. The implied consent is willfully connecting the monitor to the computer.

Avoid LG products.

HDMI can have ethernet as well, though I'm not sure how common (if at all) it is to route this through a normal video card. That might change if LG asks Asus nicely.

Or is the user conned into installing the LG app under the guise of improved monitor functionality or some such bullshit?

According to the article, the add software is installed with the drivers through Microsoft Update.