Can you get banned for flaming in TFT?

cannot confirm this but there's no reason to think the IFS is turned off in TFT

please do not tell me that your question is seriously serious

Yes you can

The terms of service and summoner's code apply to everything "League of Legends."

You're playing League of Legend's game are you not? Which means you agreed to the policy. What makes you think a mode is any different than the other modes?

Of course.