I haven't been able to verify this yet but I think my (2015) Samsung SmartTV tries to ping a specific Samsung domain to determine whether the device is connected to the Internet. Last weekend something must've happend to that domain because the TV told me it wasn't connected to the Internet and refused to start any app. The Internet connection (as well as the local Wifi connection), however, was perfectly fine.
So I expect the device (at least the "smart" functionality) to be bricked as soon as Samsung takes that domain down for good. In fact Samsung already removed 80 % of the gimmicks and remote features the TV came with, some of them didn't even last two years.
The worst part is that there isn't just a couple super popular models of TVs that people could develop custom firmwares for, there are thousands of skus for televisions and each of them may behave in a different manner meaning that at their end of life it is unlikely that any group is going to go through the effort to free them from death.
Yeah it's annoying. But at least they still have a normal HDMI input, so I could still buy a smart TV stick to plug into that (or use a laptop). That seems more and more attractive as well since after a recent software update my TV now takes around a minute to boot to its smart OS, I suspect because the old hardware can't keep up with the new software.
So I expect the device (at least the "smart" functionality) to be bricked as soon as Samsung takes that domain down for good. In fact Samsung already removed 80 % of the gimmicks and remote features the TV came with, some of them didn't even last two years.