If your chatbot is available to everyone, yes. It’s safe to assume that every single word and letter of all your documents are accessible. You can introduce another layer to prevent this if it contains sensitive data (metadata can play a big role here)
OpenAI does not use data submitted to and generated by our API to train OpenAI models or improve OpenAI’s service offering. In order to support the continuous improvement of our models, you can fill out this form to opt-in to share your data with us.
https://help.openai.com/en/articles/5722486-how-your-data-is-used-to-improve-model-performance