Disney has in-house due to their scale/licensing and are certainly the industry leader; if for no reason other than the money they spend on them. They put a major emphasis on it. But they also subcontract out plenty, in particular their "less advanced" ones and even use the same companies as Universal (Creature Tech, Global Creatures, Garner).
Universal just hasn't spent the money. But when they do, you get really good ones like Kong.
Truthfully, as I've mentioned ad nauseum; Universal can't spend as much because they don't get the ROI. The number of rooms and attendance in Orlando alone are dwarfed. Vouple that with a significantly higher worldwide attendance and park presence for Disney, and it just isn't in Universal's cards to break the bank for animatronics. Disney can and does. I'd expect the third park to outshine IoA and USF and wouldn't be surprised to see a "showcase AA" appear like Yeti (RIP), Shaman, Hondo, BatB Japan, etc.