Yeah, Tavis is a smart guy. He knows his D&D (both current and past editions), and is about as old school as it comes. He also happens to have a great sensibility for knowing why it is a particular piece of design doesn't work, but that's another discussion entirely.
In fact, the d12 has exactly seven applications in the "core" 1E rules, listed here in rough order of most-to-least important: — Damage caused to Large opponents by longsword, awl pike, and perhaps a handful of exotic/stupid polearms. — Hit Dice for barbarian class. — Determining starting age for some gnomes. — Determining starting spells for illusionists. — Determining number of followers for rangers. — Determining what's on the next page in a book of infinite scrolls. — Used by DM when rolling random NPC personalities or skill levels for professional gemcutters.