How exactly do you figure this would work?
Did Tencent say "Hey, you know about this ban system you have? I want you to include it automatically detecting things we want to censor!"? And by simple word-detection no less, since there's no way a machine learning system can pick up something that is mentioned so rarely and, I should suspect, even more rarely reported.
Or do they just hire a virtual shit ton of extra people who exclusively scan for politically problematic statements… who for some reason completely ignore all other sort of deplorable behaviour? And even then: Do you figure Tencent is micromanaging Riot so hard that they get to directly decide to ban individual players?
Yeah, I'm sorry, but I'm calling bullshit. You either have a tinfoil hat of epic proportions, are delusional about why you actually were banned or are straight up lying.
My personal bet: Since apparently you were talking about China in that game, you probably said a certain two-word phrase, both words starting with "ch" and only differing in one vowel, which is used to mock Asians and in particular Chinese.
That phrase is a zero tolerance phrase and instantly yields a 14-day ban.