Itsamystery what Apple was thinking, but I suspect almost zero external customers actually bought an ANS. Apple probably used it internally (dogfood), and maybe some external partners got one.

Sorta like CHRP "Windows NT on PPC", it was printed on the CD-ROM, but the machines were never actually sold to the public.

Also edit to clarify: OP is about porting Doom to an old UNIX, not the usual small computer. The ANS was a big computer. (OP says IBM ported Quake.)