Microsoft Office blog:
Word, Excel, PowerPoint, Outlook, OneDrive, Skype for Business, and OneNote will install and run on macOS 10.14 Mojave. No formal support is available for Office when using a beta installation of Mojave, and you may encounter stability issues. Microsoft intends to fully support Office 2016, Office 2019 and Office 365 for Mac on 10.14 Mojave when Apple declares it generally available (GA) for all users.
It’ll run, but no formal support until the official Mojave public release.