In the Guardian version of this article[1] they also mention that they let an AI control an F-16 fighter, so I think the experiments go beyond simple role-play in a ChatGPT window!
[1] https://www.theguardian.com/us-news/2023/jun/01/us-military-...
[1] https://www.theguardian.com/us-news/2023/jun/01/us-military-...