By sheerest chance I read the same anonymous Japanese basket weaving forum where a link to this was posted just before its appearance here. Well played OP.
It's from a ~daily Japanese language thread, the comment in question is simply 'reverse nihongo just dropped https://minilanguage.com/' and did not spur any further discussion. I just happened to notice it at the time and thought 'mildly interesting, maybe I should submit this to HN'. When I visited HN later in the day I was amused to see it already here.