It's well known that GW uses releases to test new ideas and ways to launch products, as they should. One of our very reliable sources has chimed in that GW is watching closely how the Horus Heresy does for The Old World Release in the future. After all both of these settings are connected in that they are the backstory for GW's primary games, 40k and AoS.
via a solid source on Faeit 212
got the information that they are using the reboot of Horus Heresy as a "testbed"
how the releases of Warhammer The Old World could look and work.
