They did refer to it as 'modular' (see posts above). However I think Apple defines 'modular' as having the display separate from the computer. Thus the Mac mini is also 'modular' by that definition.
And that's where internal consistency for Apple ends. Apple's own marketing materials state:
- Mac Pro = "modular system"
- Mac Studio = "modular system"
- Mac mini = no reference to being "modular"
Apple's marketing team so desperately wants to separate itself from the PC that they're just reinventing definitions.