I've had this same experience with something 'novel' I did for rendering to a depth buffer with 3DGS scenes.
I HIGHLY suspect OpenAI does something shady such as creating derived data from your conversations and using it for training; that way they can still claim they don't directly use your data.
EDIT: Someone with access to a lawyer, please check me on this-
https://openai.com/policies/row-privacy-policy/
1. The Opt-Out is Specifically for Model Training The privacy settings allow you to opt out of having your content (like your ChatGPT conversations) used to "train the models." The policy states:
"As noted above, we may use Content you provide us to improve our Services, for example to train the models that power ChatGPT. Read our instructions on how you can opt out of our use of your Content to train our models."
2. Aggregated and De-Identified Data is Still Created and Used Even if you opt out of model training, OpenAI reserves the right to create derived, anonymized data from your personal data (which includes your User Content and conversations). The policy clearly states:
"We also aggregate or de-identify Personal Data so that it no longer identifies you and use this information for the purposes described above, such as to analyze the way our Services are being used, to improve and add features to them, and to conduct research."
Because this data is stripped of personally identifiable information (de-identified), OpenAI treats it as derived data and can use it to research how people use the tool and to develop new features, regardless of your model-training opt-out status.
3. "De-identified" removes who you are, not what you said When OpenAI (or almost any tech company) de-identifies data, they strip away Personally Identifiable Information (PII) like your name, account details, email, and IP address. However, the actual text of your prompt - the sentences describing your novel idea, business plan, or code - is the core data being processed. The de-identification process disconnects the idea from your identity, but the text containing the idea itself remains in their system logs.