As you may know, before installing Office 365 Pro Plus it is recommended to uninstall previous MSI Office install.
While it was already possible to perform this uninstall either manually when running the Office 365 Pro Plus setup or using an XML configuration file, it was not so easy.
An updated version of the Office Deployment Tool is now available which includes a new RemoveMSI capability, helping you to properly uninstall previous MSI install (like remove all other Office products or keep some)
You can get more detail here https://docs.microsoft.com/en-us/DeployOffice/upgrade-from-msi-version
NOTE to use this new capability you must deploy at least Office 365 Pro Plus version 1803 on Windows 7 or later