Some characters and backgrounds have been updated, and they remain updated from start to finish. The new valley background will always be there, for instance, and the same goes for the new sprites we put in for Luke, Kota and Argos. Only Asterion's first set of sprites, where he's very injured have been updated, but the second batch will come out on the next update.
Considering we are approaching to the next release, I suggest you wait a bit before continuing.