I followed the official best practices on GitHub.
But in the very first step, this line confused me.😫
Unverify your company email address by deleting it in your Email settings. You can then re-add it without verifying to keep any associated commits linked to your account.
Don't worry, you won't lose any contributions only if you re-add the deleted email like they say.😌
Then following their advice, I could keep my past contributions to the organization.