The default feed on the Chatter home page is shown when a user navigates to the page, returns to it, or refreshes the Chatter home. Up to now, the default for everyone was the What I Follow feed. From now on, if someone is following fewer than 10 things, the Company Highlights feed becomes their default. New users now have a chance to see what’s most active in their org and to get ideas about more things to follow. When a user follows more than 10 things, the default feed changes to What I Follow. This feature is available in Lightning Experience.