Not sure any chairman has their ear to the ground to fully understand the culture within their organization.
I never saw our CEO in person, never saw our chairman even on a webinar.
And yes it's not their job to be that low level, but they can't have an idea of the culture either.
"Company culture" at Berkshire Hathway doesn't mean the same as at most companies. BH buys companies and don't interfere with them. So while BH employs upwards of 100k people, the people whose culture the CEO cares about is probably under 100 people.
Berkshire itself has less than 50 employees, so it's absolutely possible to do this.