Hardware WiiU Preinstalled Game bundles question

[XtremeCore]

Hi guys,

I'm planning to get a WiiU bundle that has games pre installed (more specifically, I'm looking at getting either the Mario 3D World + Nintendoland or Smash Bros + Splatoon bundle).

However, I do have some queries about how these pre installed game bundles work:

1. Do the pre installed games come pre installed per se? Or do they come in codes that require to be activated through eShop? (I read that the code system is used for Windwaker bundle, but what about the Mario 3D World + Nintendoland and Smash Bros + Splatoon bundles?)
2. Suppose that the pre installed games are not distributed through codes but are already pre installed on the console, if I do not link my NNID to the console, will the games still be available after a system format? I'm asking this in the event that I decide to get a pre-owned system due to the unavailability of the bundles I'm interested in at most retailers.

Thanks guys