Via StarWars.com:

Lucasfilm has confirmed new dates for the launch of Star Wars: The High Republic, due to general marketplace delays.

Both Charles Soule’s adult novel Star Wars: The High Republic: Light of the Jedi and Justina Ireland’s middle grade novel Star Wars: The High Republic: A Test of Courage will both now release on January 5, 2021. Claudia Gray’s young adult novel Star Wars: The High Republic: Into the Dark has moved to a new release date of February 2, 2021.

New release dates for Marvel’s Star Wars: The High Republic series and IDW Publishing’s Star Wars: The High Republic Adventures series will be announced at a later time.

Star Wars: The High Republic is set in an era when the Galactic Republic and the Jedi Order are at their zenith, roughly 200 years before the events of Star Wars: The Phantom Menace. This period on the Star Wars timeline will not overlap any filmed or planned Star Wars movies or series, giving creators a blank canvas and a vast amount of creative room. There will be new worlds, new foes, new heroes, and new adventures.

Lucasfilm Publishing creative director Michael Siglain provided StarWars.com with the following letter about the change:

For more on Star Wars: The High Republic, stay tuned to StarWars.com.