What is behind the new Office 365 Network?

Hi Massimo, 

The roadmap and investment in Yammer remains the same. We choose to move the community to a new platform because we wanted an un-authenticated viewing experience. With Yammer, members needed to sign up to view any of the content, and responses didn't show up in Bing/Google search results. 

For for information on why we made the move, here is a link to the official blog post. I also recommend taking a look at MVP Naomi Moneypenny's blog on the topic here. 

The decision to move was made indepently of the announcement you referenced and has been in the works for some time as we realized we needed to reach more customers while continuing to provide a great community experience. 

In short, Yammer is NOT dead, it's alive and going strong- with plenty of devoted resources and team dedicated to bringing additional features in the coming months. You can always look to see what's been publicly announced on the Office Roadmap.