The insides of the joycon's joy stick show an almost identical design, with the inclusion of a plastic covering (possibly to reduce dust build up) and slightly smaller washers/covers (as shown in the picture below, with Joycon 2 on the left, and in 6:01 of the teardown video)
Joycon 2 image with slightly smaller washers/covers. (via TronicsFix)
Previously, the washers of the original Switch would wear down overtime, causing stick drift. The new and 'improved' Joycons' simply reduce the size, with hope to increase the lifespan of the sticks.
As mentioned by many reviewers, they are not hall-effect. It is likely that the magnetic attachment of the Joycons mean hall-effect sticks were not possible, as they require magnetic sensors to function, which may interfere.
by ProZapz