If you're planning on using the TV as a dumb display for another device, and are determined enough to physically remove a cellular modem, then the TV's own WiFi is not a useful thing either, even if integrated into the same chip.

The CPU, wifi, and modem are all in one in this future (think ESP32). That is the direction this is likely to move. You can't remove one without the rest. I suppose you could put your own CPU in and write software, but otherwise you are stuck.

If you want the TV to be on your network (for casting or streaming or whatever) and you also want to filter that traffic (allowing connections only to the services you want to use) then you need it to be on your own network (wifi, if there's no ethernet port) and not on someone else's network (cellular).