Comment by ninkendo

So?

All the letters in this string are “just text”:

    "\u0000\u0089\uDEAD\uD9BF\uDFFF"

JSON itself allows putting sequences of escape characters in the string that don’t unescape to valid Unicode. That’s fine, because the strings aren’t required to represent any particular encoding: it’s up to a layer higher than JSON to be opinionated about that.

I wouldn’t want my shell’s pipeline buffers to reject data it doesn’t like, why should a JSON serializer?