Science is not an ideology or opinion; in a diverse environment, reasonable positions are disputed by arguments, not power play.
Exercising an executive bias to intimidate the employees into subscribing to a specific ideology is nothing this code of conduct were able to prevent. The coc could not perform worse measured by it's own goal.
It's no service to any code of conduct intention if a code of conduct is treated as some chilling orthodoxy that is used to prevent a communities open dialogue and self awareness.
"Women, on average, have more neuroticism (higher anxiety, lower stress tolerance)." isn't a reasonable position at Google, or any other big company. If for no other reason, to protect the company from being sued for gender discrimination.
Neither are any of the following statements reasonable:
"Blacks on average are... [insert some negative]".
"Jews on average are... [insert some negative]".
If an employee can't figure that out, you should fire them with zero hesitation. Open dialogue at a place of employment has many limits, and it will never be the top priority. If you say something that offends enough other employees, you're going to get fired, and that's not going to change no matter who you work for.
What's confusing or unclear about that? It's crystal clear to me that Google prioritizes a workplace free of harassment over your individual ideology. If your ideology makes other employees feel harassed or intimidated, you'll have to leave your ideology at home.
And if you're not clever enough to understand that a statement in a widespread memo like "women, on average, have more neuroticism (higher anxiety, lower stress tolerance)" could cause one gender to feel intimidated or harassed, then perhaps you're not clever enough to work at Google.