Will Teams Ever Be Designed To Work With Networks?

forrestdean I work for an organisation with 300,000 staff, and Teams works very well for us, so I'm not sure really what you mean by working with a Network.

Some suggestions.

1. You are perhaps on the right track with one team if your organisation has less than 5000 staff, then using channels for departments, it's a good and open way to work. Show your users how to use Show/Hide to keep only their department in view, then when someone @mentions that channel only the people who show the channel will be alerted. It's not a security boundary, as you observed that would prevent departments talking to each other.

2. Many people don't really work as a department, more as cross department teams to deliver a specific project or goal. Teams is great for this, create workgroups where they can hold all the resources in that one place for that subject, every file, message, tasks, even the web apps they need. It's like self filing into a common context.