Asking somewhat obscure hard data (like a date) from a LLM is pretty much futile even without knowing anything about LLMs: They are smaller than all the factual knowledge in the world so a lot of it won't be there. If it answers, it's probably a hallucination.

The current offerings of OpenAI and Anthropic can be asked to support their claims by for example reaching out to the internet and citing reputable sources. That improves the answer quality for questions like this immensely and in any case they can be verified.

Also the question asked is spurious: It appears there never was a release date for this particular SKU given by Cisco. The whole series (Cisco 1000 Series Integrated Services Routers) was released on 06-OCT-2017.

https://www.cisco.com/c/en/us/support/routers/1000-series-in...