Note that it's a bit different this time as Haedrig's Gift, which enables you to get to T6, requires quite an effort this time.
The changes to completion of Chapters instead of individual objectives actually slipped by me, so good pickup there but I'm pretty sure its only T4 for Chapter 4? I haven't levelled a toon on S7 PTR yet but last info from Nev was:
http://www.diablofans.com/blizz-tracker/topic/62583-patch-2-4-2-focused-feedback-season-journey
Chapter IV - Completing rewards 3rd/Final Haedrig's Gift + New Portrait Frame and Pennant