Hello,

Communication is very important in an organization. According to my current site manager, Transparency between different site/organization site is very important. what He meant by transparency is that we need to communicate. There should be a good flow of communication between the upper management, lower management, with people who run the operations. So, for your first question i thing there is no one person that can do all the communication, It’s a flow.
Communicating with your project stakeholders-your team members, the project sponsor, and anyone else with an interest in the project- is critical during all the project management process. Through ongoing communication, you keep stakeholders apprised of how the project is processing, what problems you’re encountering, and ow you’re dealing with the problems. Regular communication also maintains project team commitment and ensures ongoing support from your project sponsor and other stakeholders

For you second question, i would like to say that for a professional situation launch meeting /face-to-face launch meeting is a good platform for communication. For an operation meeting or team meeting there can be different approach in different organization. In my current job we do have everyday 15 minutes Huddle meeting, were the employee address current day issue and try to resolve it.