DemocracyFTW2 parent
Well it does lack that final -e of archive, and—fun fact!—like LaTeX which I know as ['la:teç], arXiv could plausibly be pronounced [ar'çi:f] in German although I've never heard anyone pronounce that name. So why is it arXiv not at least arXive with an -e?
Because they're trying to be quirky I guess, but it is still unmistakably a weird spelling of "archive" (especially given the context).