Might look at switching to something like cronycle.com or Facebook at Work?
http://venturebeat.com/2016/09/26/microsoft-is-killing-yammer-enterprise-in-january-2017-will-start-integrating-office-365-groups-first/
http://venturebeat.com/2016/09/26/microsoft-is-killing-yammer-enterprise-in-january-2017-will-start-integrating-office-365-groups-first/