I got an LG OLED with the Homekit implementation from LG and I can disclose that officially from LG support that their implmentation does not allow to switch on the TV from Siri or any Homekit command.
They have a major bug for all their TV which once off, just power off the Wifi or Ethernet connection which kills any chance of connecting to it, so once it is off, it is unreachable from an homekit/Siri perspective.
So do not even say they will support Homekit as they won't ever and when I ask when this bug will be fixed, their answer was clear: never.
I just returned the LG TV and went for Sony which has a great Homekit implementation