Does macOS Mojave (10.14) support 32 - bit Apps?
Yes

As of macOS Mojave (10.14) beta 9, macOS Mojave DOES support 32 - bit applications. When opening these applications, you will see a dialog box with a similar message from High Sierra (see below) telling you that "This app will not work with future versions of macOS" but after clicking "Ok" the application will open.

For example, I attempted to open an old version of Firefox (3.16.14 from 2010) that is 32 - bit and got this message



After pressing "Ok" it opened





Sorry about Spanish, only version I could find.