It all depends on your definition of reskins and uniqueness. Reskins = Another texture, same model as standard Unique = Different or one texture, new unique vehicle model Who says that the new model have to have other stats? It will look unique, yes, but it's really the same as any other reskins.
Could be a unique vehicle (i.e. not just a reskin) to the founders but with the same stats as a regular in-game vehicle?
But then everything is a skin of a skin of a skin of skin of a.... Uh oh, I think I invoked a lesser daemon of Slaanesh
They already stated that Weapons you buy are about 20% weaker then the in-Game weapons. Also I don't think the unique vehicles are ment to be p2w stuff, how I understand them, they are strictly against such policy. However, I have things like Razorbacks, Daemonmounts and other things in mind which are in some ways more powerfull, but have other weaknesses compared to akin vehicles. Rember the asymnetrical balance system
This is a bit ambiguous. In 3d modelling, a reskin is very specifically when you recolor and retexture a model. In common parlance, on the other hand, a reskin is generally when you change any cosmetic aspects of a thing; i.e. everything that matters stays the same. For example, the game Smite has been updating its character models since beta started. It has also, occasionally, updated the skins without changing the models at all. Technically speaking, those are different processes. Colloquially speaking, they are both reskins (since the in-game powers are unaffected by cosmetics).