Make conversations public by default. If you use Slack, make team channels, project channels, announcement channels etc. all public. Discourage 1:1 and private communication unless really necessary, especially for engineering topics. This single change will have an immense impact on overall company culture.
I've worked with many great people that hate to handle things without their usual group first, and will stall until a reasonable approach can be presented. Which means creating shadow communication process - the more you push for "discouraging 1:1" the more they will hide.
What your organisation did with such "incompatible" people, relate them until the team left likes how they work, or were there better ideas?