It seems like you can disable the data being used from training by turning off gemini app activity.
> You can turn Gemini Apps Activity off
If you don’t want future conversations reviewed or used to improve machine-learning models, turn off Gemini Apps Activity Opens in a new window .
> You can turn Gemini Apps Activity off If you don’t want future conversations reviewed or used to improve machine-learning models, turn off Gemini Apps Activity Opens in a new window .