Courtesy of Wizards of the Coast (WotC) and Mark Rosewater, the enemy color temples and Fabled Passage are being reprinted in Core Set 2021.
Rosewater previewed Fabled Passage, which was originally printed in Throne of Eldraine, while the mothership revealed the temples that were reprinted in Core Set 2020.
All of the lands previewed today are already in Standard, though the enemy color temples would rotate before the other five reprinted in Theros Beyond Death. Bringing them back in Core Set 2021 will keep all the temples together.
While opening these rare lands in packs isn’t that bad if you already own them, players on Arena that already have playsets of them are stuck opening duplicates of cards without new art. Players on Twitter have already acknowledged that up to 24 rares opened from Core Set 2021 on Arena will be useless.