This is, of course, a very sad story. It's certainly possible that ChatGPT was involved, although with OpenAI's neutering of the model, it seems more likely to be a different chatbot.
Either way, it's lazy of the article to not resolve this ambiguity, and seems rushed. It's not the case that "chatbot" = "ChatGPT" in 2023.
Is this chatbot named Eliza actually Eliza and not ChatGPT?