No, it hasn't. Even where people were just submitting reports from an automated vulnerability scanner, they had to write the English prose themselves and present the results in some way (either in an honest way, "I ran vulnerability scanner tool X and it reported that ...", or dishonestly, "I discovered that ..."). This world where people literally just act as a mechanical intermediary between an English chat bot and the Hacker One discussion section is new.
Slop Hacker One reports often include videos, long explanations, and, of course, arguments. It's so prevalent that there's an entire cottage industry of "triage" contractors that filter this stuff out. You want to say that there's something distinctive about an LLM driving the slop, and that's fine; all I'm saying is that the defining experience of a Hacker One bug bounty program has always been a torrent of slop.