No, fonts are not part of an ARCHICAD file. I'm not aware of fonts being part of any application file, other than a PDF which is based on the concept of font-embedding. You'll have the same issue with any other CAD file, a Word doc, Photoshop text layer, etc when moving between machines.
So, if anyone involved in a project uses a non-system-standard font, they must distribute that font (if it is a freely licensed one) - or provide a purchase link (if it is a licensed one) to all other users.
For both Windows and Mac, it is pretty easy to zip up a font file and send it to another user on another system.
AC 28 USA and earlier • macOS Sequoia 15.3.2, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB