Source: https://icv2.com/articles/news/view/43973/wizards-coast-reveals-magic-the-gathering-sets-2020

Wizards of the Coast revealed the names the new Standard-legal Magic: The Gathering sets scheduled to be released in 2020. The announcement was made on their Twitter after a Throne of Eldraine spoiler countdown.
In Q1, Magic: The Gathering players will be returning to Theros, the planewalker Gideon’s antiquity-themed home plane. Gideon was killed in the War of the Spark timeline, so the title of the set, Theros: Beyond Death, might be an allusion to a plotline to rescue him from the underworld.

Q2 will see the release of a new plane, Ikoiria: Lair of the Behemoths. According to Mark Rosewater, Magic’s lead designer, “It’s a monster world!” where players will get to make their own monsters.

Core 2021 will hit stores in Q3, and it is expected to be akin to their yearly base sets.

Finally, Zendikar Rising is set for Q4. The Eldrazi are gone from Zendikar, and now, the native inhabitants take shape on a plane of adventure.