[throwawayboise]

NeXT had already done the work to support M68K, Sun/SPARC, HP PA/RISC and IA-32 before Apple acquired them. They have been architecture-independent for quite some time.

[einherjae]

The technical support yes, but the install base of NeXT users were fairly negligible comparatively.

The real trick was in transitioning the user base in a fairly smooth fashion, and then doing that twice more in the following decades.