As a Govt. Contractor supporting multiple Data Center installs that will never be able to be hosted on Commercial Cloud, you are missing out on a huge opportunity.  Never mind they will eventually just move everything over to Sharepoint instead as a result of lack of capability in Data Center and the cost.

Costs for datacenter are getting up and up and up and up.
But no real new functions are given. (The same for Jira btw)
So please start honoring also the data center customer (since they must have a reason to use data center) and give us new functions like whiteboards.

Just to capture info from https://www.atlassian.com/software/confluence/whiteboards 

FAQ on that says

Is Confluence whiteboards included in data center?

Confluence whiteboards is a cloud-only offering, and there are currently no plans to bring Confluence whiteboards to Data Center. We will continue to investigate the opportunity and share plans if that changes.

We as DataCenter users also pay huge amounts of subscription costs. So why we should be treated worse than Cloud customers. Even that Atlassian always promotes that there aren't any reasons for not using their cloud products we can only say that for enterprise companies there are many very good reasons to not work in the cloud. Especially for those that have started 10 years ago to work with the Atlassian tool suite and have highly customizes environments that are interfaces in many ways with other enterprise applications. Migration to Cloud, with all apps from that 50 % are not available in the cloud at all because of restriction's and the other 50 % has often only reduced functionality because of restriction's in the cloud, is still a nogo for those customers.

So please honor this decision and give us something back for the high subscription costs (10 Times higher then the server maintenance costs 6 years ago)