Microsoft team is now building new DataCenters for Office 365 across the globe for better performance and expand the service. Once these new DataCentres are setup in a specific region Microsoft team will start to notify tenants that will participate in the move to the new DataCenters in advance with set of vital instructions to follow during the activity, Since this is a DataCenter move during the cut over phase there will be some impact to the Office 365 services.
To know more on this topic Microsoft Office 365 team has published the below TechNet post recently explaining the background of this process and what to expect during this activity in detail.
Below is the extract from the post explaining things in a nutshell.
Access the post here: Datacenter changes for Office 365
Review the FAQ section in the post to get your queries clarified.
Since user services are impacted review the Before your datacenter move, During your datacenter move and After your datacenter move articles clearly and send user communication on time and set exceptions to the end users to avoid support calls to your support teams. Also contact Microsoft support to get things clarified if you have any queries un answered with the available resources and utilize the trial if you wish to check things in the new region before the move. Finally, if you really want to stay as is and stop the move contact Microsoft support and update them timely as explained in the post.