Notifying users about new features

We use Teams. I have a team called 'Office 365 Training' where I keep a Planner plan that has all the announced/released features. It's a public team and I've posted the join code to different places that people frequent so people know it exists. They can follow the channels they care about. We don't globally push the information because only part of our company is on Office365.

Once a feature shows up in our tenant, I'll post about it in the appropriate channel. I also start a conversation each Monday in the General tab called 'Tips for the Week of (date)'  where I'll mention anything new, either new feature or a training tip.