alt Hacker News> The only thing I'm not sure about is why they decided to reopen it.
It's almost certainly due to the PDF Association adding JPEG XL as a supported image format to the ISO standard for PDFs; considering Google's 180 on JPEG XL support came just a few days after the PDF Association's announcement.
That would make sense, since they would then need support for JXL for the embedded PDF viewer anyway. Unless they want it to choke on valid PDFs that include JXL images.