After several hours, the HN title has been modified again to match the original much more closely, from "Hannah Cairo has solved the Mizohata-Takeuchi conjecture"[1] to "Hannah Cairo: 17-year-old teen refutes a math conjecture proposed 40 years ago".
"A 17-year-old teen refutes a mathematical conjecture proposed 40 years ago"
The site's guidelines are clear[1] but increasingly ignored by some moderators:
"...please use the original title, unless it is misleading or linkbait; don't editorialize."
[1] https://news.ycombinator.com/newsguidelines.html