Didn’t know this week’s discussion even existed 
Anyway, found this while looking it up:
Reading does not match Kanji
As I thought, it’s just a new degree of freedom that Japanese people have. The kanji mean one thing and the voice/kana have another meaning. You can put the two together for a new, combined and unique meaning.
I am following a shounen anime currently airing ( Mairimashita ! Iruma-kun) and it’s full of kanji being replaced with other kanji that sound the same but are demonic/hellish. And then there’s villains having weird kanji that are related to death (死) etc. that I doubt anyone would choose for their own children.
As I said the Japanese language has one more degree of freedom than our poor phonetic languages, I think it’s something we should always keep in mind.