The 6.4 kernel has been released

It's an XKCD 1172 moment. All behaviours are subject to Hyrum's law, regardless of whether anybody consciously added them, whether they're a typo, or even a really wild coincidence, if you've got enough users somebody is relying on the very stupid bug you wrote, and sees it as a valuable feature. This isn't a bug, but it's not a very good feature, and so it's sensible to remove it.

In a few cases Hyrum's Law means you're stuck with it in practice e.g. HTTP "referer" headers. But in most cases it's just not that many people, and they'll get over it, and if this was the most annoying change for you in 2023 so far you've had a very good year and maybe shouldn't draw attention to that.