In my experience, it's working correctly these days for gemstore skins, but still bugged on default skins. It's more pronounced the longer your load times are (due to slow hard drive, full memory, whatever). When the mount skin is still loading, the camera is stuck in one spot, though the invisible mount is free to move around. Once the skin loads, the camera snaps to the mount's location. If the player dismounts before the skin loads, they find themselves at the stuck camera location instead of the mount location (that is, they are teleported). Only happens for me with default skins, so I mostly notice it on my key farm characters or skyscale.