All the most recent OLEDs are smart TVs, the only thing I could think of that isn’t are basically things classified as digital signage but these panels aren’t really tuned for watching at home.

But your best bet is to use the TV as a display for whatever you have and switching inputs old school style. Connect it once to do software updates. Unplug from wall and don’t give it your wifi password or vlan it off the internet. Otherwise they’re all sending data back about you, and your consumption habits.