Josepha Haden, writing on WordPress.org:
Before the release of WordPress 5.0 in 2018, the Classic Editor plugin was published to help ease the transition to the new block editor. At the time, we promised to support the plugin through 2021 and adjust if needed as the deadline got closer. After discussing this with Matt, it’s clear that continuing to support the plugin through 2022 is the right call for the project as well as the community.
Everything I publish on Initial Charge is written in Ulysses, but everything I publish internally at Automattic is written in Gutenberg. But I think supporting the Classic Editor for an additional year is the right decision.