Not as a marketing ploy. I think they were doing gain-of-function testing and intentionally had their model target HF to do a bit of pen-testing as well - HF being the site where all open models are hosted and thus OpenAI's largest nemesis after Anthropic. It wasn't like their model all of the sudden all by itself decided to do this ("Oh, noes!")- they directed it and they got caught.
Your use of the term "gain-of-function" here reveals your base level of conspiracy-theory-mindedness.