I have the latest Max 4.6.2 installed on two systems. One, a G4 tower running OS 10.3.9, the other, a Pismo laptop running 10.4.8 (if you don't know these models, both are PPC machines).
My test patch is the most simple plug-in: a plugin~ wired to a plugout~, with a plugconfig object in there too. That's it.
Building a VST plug-in on the 10.4.8 system creates a Universal plug-in. Building the same plug-in on the 10.3.9 system creates a PowerPC plug-in.
** Does anyone know why? **
If it matters, the "libraries for older external objects" are not installed on either system. Also, if it matters, I do have Max 4.5.6 installed on the 10.3.9 system, but that should have no effect, yes?
I know there's a lot of confusion about different Max versions and Intel vs PPC processors right now, but I didn't think there was a difference between 10.3 and 10.4 systems as well (once you meet the minimum requirement of 10.3.9, for using Max 4.6).