Nope, not at all!
I am basically adding extra scenes in between the already present content, as well as fixing and improving the scenes already in the game. There are no new choices, or anything that will require a new playthrough, only if you want to see them.
For the sex scenes, if you already played through them once, they should be unlocked in the gallery already, so you can just go there and access them through the replay feature, they will already be the new reworked ones.
The gallery images will also already be unlocked, you can still unlock them playing normally, but after the patch comes out, you just need to roll the final credits and they will unlock automatically, no new playthrough required either (this was on me because I screwed up the gallery before releasing chapter 3
)
