As of Gutenberg 11.8, it looks like default theme supports are automatically added, including editor-styles
|
// Add support for editor styles. |
|
add_theme_support( 'editor-styles' ); |
On a local install, I commented out those lines ☝️ and editor styles still loaded as expected.
Tested with:
WordPress 5.9.1
Gutenberg 13.2.0
Frost 0.9.6
Happy to submit a PR.