If you want to encourage a specific culture you do this by starting with a small set of people who have this culture in their bones, then growing slowly and assimilating more people into that culture, addressing deviations swiftly and letting people get back to their work afterwards, without skipping a beat.
Not by writing manuals, and then stressing everyone with looooong, reaaaaally long and exhausting "we need to talk" style posts, where we hold hands, talk about how it's so difficult to open your mouth and say something that's not offensive, and how we're far from perfect, and in fact, we're all sinners.
It's not that the intent is wrong. But this way of going about it is so extremely taxing on everybody, creating an atmosphere where everything people say is judged on the "-isms" scale.
It means when you talk, you're terrified of what you're saying.
When you listen, you listen for someone to say something so you can point your finger at them.