Here is a list of 40K Successor Chapters, and Campaign Zones being published in White Dwarf ...
WD 456
Sep 2020
Silver Templars
WD 457
Oct 2020
Argovan Campaign Part 1
WD 458
Nov2020
Tome Keepers
WD 459
Dec 2020
Argovan Campaign Part 2
WD 460
Jan 2021
Emperors Spears
WD 461
Feb 2021
Charadon: The Alumax System
WD 462 ... Mar 2021
Excorists