I'm quite interested in seeing how you get this resolved as my Word and Excel are 32 bit and I've been thinking about the standalone Office as one option for getting to Mojave.
I upgraded to Office 2016 before Mojave was released, so I can't say it with 100% certainty, but I don't think you should have any problems running the 32 bit version until macOS 10.15 "La Brea Tar Pits".
Also, as I posted to andycap, com.microsoft.word doesn't exist in my Mojave 10.14.2 installation...visible or invisible.