Here’s a note from the Office 365 admin center:
Office ProPlus and Office 2019 will now be installed with 64-bit as the default setting. Previously, the default setting was 32-bit at installation. This change will begin rolling out in mid-January, 2019.
After this change takes place, the 64-bit version of Office will automatically be installed unless you explicitly select the 32-bit version before beginning the installation process.
If you install the 64-bit version, but wanted the 32-bit version instead, you must first uninstall the 64-bit version before installing the 32-bit version. The same is true if you installed the 32-bit version but want to install the 64-bit
--Joe
