I certainly take you seriously. You are, as an analogy that isn't really an analogy, that one poster who is not posting "wow zoe OP" on gameplay, but instead actually posts reasoning :P
I can kinda understand where you're coming from - in which words may have different meanings online, but I cannot say I agree with that. I think one of the reasons 4chan uses that word is precisely because of its hateful meaning and the fact that 4chan is a shock site. I don't think words can have different meanings just because of the manner in which they are written/spoken.
I do agree that in some contexts words may not be hateful. As you say though (rap music and/or possibly black friends - I use the term black as it's the term we use in the medical field, as African American is both a misnomer and could lead to deadly consequences if we mislabel people during treatment, but I digress) - there are some very limited circumstances in which the word may be acceptable. I also do not subscribe to this idea that floats around that "the n word is okay when X people [race, color, gender, area of the city, etc] use it but nobody else" - that is literally antithesis to what they purport to be for (the desensitization of the word). You cannot take a racist word and through racism eliminate the racism. I digress again, I think.
The point I'm trying to make is that while these are great social debates to have, there is no situation in a video game where those words are okay when strangers are involved. If they're okay between friends - then fine - your friends won't report you. Once there's a stranger, they aren't your friend - thus it is no longer okay to use. If the word is okay when certain population use it, that is your opinion - and if you're with 4 people who share that opinion, fine, they won't report you. But when there's a stranger, you do not know their opinion on the word, and they may very well subscribe to what is still the majority view in the NA region that it is hateful.
I can all but guarantee that Riot is constantly reviewing their systems. I sincerely do hope that we can get rid of racism - it's a wish for world peace, but I can hope. We may get rid of these words from the vocabulary entirely, or they may lose their racist connotations. However, we are nowhere near there yet, and for many people, the "n word", "c word", "f word", and especially the "r word" have great potential to reopen wounds that are closed and nowhere near healed. I have my own personal story regarding one of those words and why I absolutely hate seeing it used by a stranger, but that's not what this post is for. The bottom line to me is that a video game is not the place to test words meanings or rewrite them.