I love it!
As for the claim that "literally" ever means "figuratively", I have never encountered that use - including in examples offered by those who claim its existence. Literally is sometimes used in figurative circumstance, but I would argue the use is hyperbolic - in the same way we don't say "'days' sometimes means 'minutes'" because people say "I've been waiting for you for days". I have never seen an example that would not have been understood to be figurative but for the addition of "literally".
Then again, I'm a grammatical traditionalist: I consider English to not have a male gender, but rather the three genders "inanimate", "female", and "animate".
The prescriptivists have lost this debate, comprehensively. There may be a language that lacks a gender-neutral singular "they", but it isn't English.
I think novelty is a bad choice of word here, as that has a connotation of being related to time and exposure, which makes your statement seem somewhat contradictory... I think the word "controversial" that Thomas uses is more appropriate. I'll continue as if you had used that instead.
I do agree, that length of attestation does not necessarily mean a feature is non-controversial. But I do think it is likely a prerequisite for being non-controversial, precisely because it allows the usage to be non-novel.
Ironically for a grammatical traditionalist making a comment about grammar, this sentence is not grammatically correct.