Of course there are delays when things are coming out and this rumor points to it and shows us when we could expect to see the Horus Heresy released this year. Recall that the rumors point out to a big release with a new boxset.
via a source on Faeit 212
The release of HH was delayed to Summer 2022.
GW have still some issues with their printings from oversea which hurts
their release schedules. They started to build up capacities to print
in-house again but this will need some time.
Their releases lie already 11 months behind their plannings from before
covid.
