Man, how many games has Atlus re-released in the SMT series since the original release of Persona 4? It feels like they don't want to make new games anymore..
Well, we got a bit spoiled in the PS2 era. Pretty much everything post Nocturne was much easier to make since they could reuse the engine and art assets. In theory, we'll see something along the same lines when P5 finally comes out.