Is it always a separate board? I'm not too familiar with TV boards, but most other things designed to run embeded Linux have the Wi-Fi at least soldered on to the board, and at most part of the same SoC that contains the CPU.
Perhaps not always, but in many popular models like the LG C-series, the WiFi hardware is a separate board:
https://partpricecheck.com/parts-lookup/lg-oled65c5aua-oled6...
Perhaps not always, but in many popular models like the LG C-series, the WiFi hardware is a separate board:
https://partpricecheck.com/parts-lookup/lg-oled65c5aua-oled6...