The functionality to make it possible to change the name of an O365 tenant, especially with Sharepoint Online in mind, is being planned. There is no ETA at this time though.
4,742 votesworking on it · AdminBarbara Feldon (Office 365 Customer Experience, Microsoft Office 365) responded
Great news! This capability is included in in the recently updated Office 365 Roadmap entry: “Admin App Launcher Customization Tools” which can be found in the “In Development” section.
An error occurred while saving the commentManne commented
Thanks everyone. Couldn't agree moore. Microsoft, plaese make this happen!