This is an interesting emergent trend though because it's designed to evade automated content moderation. The whole point of "PDF file" is that it's perfectly innocuous without an understanding of the surrounding context. With real-time audio transcription increasingly common, even livestreamers have to do this to avoid getting hit with automated bans or deprioritization.

There is a long history of euphemisms taking over - one day we may say "unalived" as a perfectly normal replacement for "killed", just as we don't call bears "arkto" or "ursa" any more, we just euphemistically call them "brown things", i.e. "bero" in protogermanic hence "bear" in English.