>If we could get our hands on the SoC datasheet then its possible we could flash that SoC to run whatever OS we want and actually have a Smart TV instead of a spyware and malware vector

Surely it's more straightforward to buy a SBC yourself and plug that into your TV? Even if you could flash it, dealing with random SoC/hardware seems not worth the hassle compared to shelling out $50-200 for a SBC that you picked and can be carried between TVs? Flashing third party ROMs like lineageos makes sense because there's no real alternative for smartphone hardware, but the same isn't true for smart TVs.