This PDF is not a real form like https://www.irs.gov/pub/irs-pdf/f1040.pdf, where you can just type directly and check checkboxes. The PDF shown in the what's new page is to show that even PDFs that are not correctly formatted as forms can still be f...
And there is an idea about that which you can vote: https://connect.mozilla.org/t5/ideas/add-ability-to-translate-input-text-in-a-standalone-page/idi-p/10849.
