It's both. Now, normally I'd say remasters and remakes are not systems seller. H2A, for example, would be great but it'd sell on nostalgia to those that have already played it (and likely would have bought an X1 anyways for Halo).
TLOU on the other hand, is a bit different in my opinion. It's a more recent title and in every single top related to it there's always a few or more posts that talk about how they only owned 360 and regret missing out. For that reason I think TLOU will definitely move some systems. A lot of people missed out on it last gen since PS3 wasn't the dominant console (especially in NA). Now that it's out on PS4, they can make the right choice and jump on that to experience the game. It'll definitely move systems.
Now, how many systems? Who knows, it obviously won't be a GT, but it should provide a boost and move people on the fence into buying a PS4.