Aside from Welcome To... Chichester 3 coming out sometime between the end of 2019 and early 2020 (depending on how quickly the backgrounds are done), there will be a sequel to Welcome To... Chichester 2, which is set directly after the events in that visual novel (early video here and here)
I'm hoping it will be out well before the end of the year, but again, it's all dependent on graphics (especially as there are new characters).
In addition to that, the backgrounds to Redux are being updated as well (and there will be a new DLC for that), as well as a few dialogue changes.
And then, after that it's the last series. I haven't yet decided whether to do one large visual novel or split it into three yet, so we'll see.
Of course, it will cover who (or what) killed Cindi (and why), what happened to Grendel's father (as mentioned in Redux/1) and various other bits too.
Hopefully, I can also start getting The Mansion converted to a visual novel and finally released too