Yep, this is exactly correct. Conventional transmissions have clutch packs that slowly wear over time, so the fluid has to deal with this clutch material. I've never been one to buy off on lifetime fluids in most cases, but for these cars is probably pretty accurate.
Me being me, I would opt to change around 100,000 miles to ensure the best possible lubrication of these expensive components going out of warranty. I don't think the motor would care, though. It would make me feel better, though, and for a nominal cost probably worthwhile in my eyes.