The people I know in my program (undergrad History) use their computers for little more than Google Chrome (specifically Google’s Office suite), a PDF reader (sometimes also Google Chrome), sometimes Zotero, and sometimes MS Word. We get a lot of Mac’s around here, so one can imagine Microsoft products are not highly relied upon, generally speaking.
Everything’s through the browser nowadays, so I’d say just pick a stable distro, install 2 or three browsers in case something doesn’t work (like Google Docs with Firefox in my experience…), and submit everything as PDF.
Can’t speak much to LibreOffice as I write my papers in Typst (and before that in LaTeX, which got me brownie points with some of the older professors), which I find much faster, easier, and more flexible than WYSIWYG word processors.