According to the GitHub Copilot features settings page, users can opt out of allowing their code to be used for training. The page is located at https://github.com/settings/copilot/features. https://github.com/settings/copilot/features

The default setting after April 24 will include private repositories in Copilot training data for users who have not opted out. The page specifies the April 24 cutoff date for the change. https://github.com/settings/copilot/features

The same settings page confirms the opt-out toggle applies to private repos and is listed under Copilot features. No other sources were used. https://github.com/settings/copilot/features