If you’ve got a question about how the Azure DevOps Services are billed then this FAQ is worth a read: https://bit.ly/2RvUDKt. There’s also a section on multi-organisation billing which was recently announced here: https://bit.ly/2yNdPwM, and enables businesses with more than one Azure DevOps organisation to pay for each user once for all organisations under the same billing Azure Subscription.
Microsoft announce that Office 2016 will continue to be able to connect to Office 365 services through October 2023. The previous support policy mandated that after 13 October, 2020 customers would be required to have either Office 365 ProPlus or Office 2019 to connect to these services. Find the announcement towards the bottom of this page: http://bit.ly/2N3kqty.