My experience is, written communication don't exist until I've mentioned a summary of it in a verbal communication.

Some people are not comfortable to express their annoyance until it crosses a point of no return. You have to proactively seek to bring out their disagreements, and resolve them.

Until you've experience in resolving a number of conflicts with the persons involved, to the extent you understand them on a personal level, you have not achieved trust. In that case, reducing verbal communication produces fuel to create an environment of mistrust and suspicion.