The article states that's what the privacy policy sais samsung can sample every 500ms and LG every 10ms. It doesn't really mean they are, but it's definitely possible. A very basic way of detecting content is to take a 1000 pixels evenly spaced out over the screen and store the color values. That gives you something you can match against a database. You don't need to process a 4K screenshot for this.

I watch TV through my computer using Jellyfin. Am I at danger?

We probably have the same model - the one with the big oval stand. Every once in a while I wish it was OLED and/or higher resolution, but it's not worth the expensive or all the modern "features" such as these.

Just create a black hole network at your house and connect all 'smart' appliances to that. Block all traffic at the router level. This prevents them trying to connect to open mesh networks and also provides the benefit of cataloging all the traffic

No it’s not.

Still got an old Panasonic plasma from 2010 and it’s going strong.

But I am aware of the “wonders” of post-purchase monetization, which is how they’re printing out so many of these cutting edge OLED big screens for surprisingly low initial purchase prices

It's the same thing apple's Find My runs on. Devices bounce off each other like the fires of gondor

Other than your PC or Mac spying on you, you are in no danger.

We'll see how calm you are when your TV goes live on sky net and kills you in your sleep

Who said

At this point I'm just going to assume George Orwell was a time traveler. He's been right about everything so far.

Still gonna need a large screen somehow unless you watch all your stuff at the desk or through a laptop.