diff --git a/wp-includes/nav-menu.php b/wp-includes/nav-menu.php
index 8fceeb750e..c289c2c916 100644
--- a/wp-includes/nav-menu.php
+++ b/wp-includes/nav-menu.php
@@ -406,11 +406,10 @@ function wp_update_nav_menu_object( $menu_id = 0, $menu_data = array() ) {
 /**
  * Save the properties of a menu item or create a new one.
  *
- * The menu-item-title, menu-item-description, menu-item-attr-title, and menu-item-content are expected
+ * The menu-item-title, menu-item-description and menu-item-attr-title are expected
  * to be pre-slashed since they are passed directly to APIs that expect slashed data.
  *
  * @since 3.0.0
- * @since 5.9.0 Added the menu-item-content parameter.
  *
  * @param int   $menu_id         The ID of the menu. Required. If "0", makes the menu item a draft orphan.
  * @param int   $menu_item_db_id The ID of the menu item. If "0", creates a new menu item.
@@ -449,7 +448,6 @@ function wp_update_nav_menu_item( $menu_id = 0, $menu_item_db_id = 0, $menu_item
 		'menu-item-attr-title'    => '',
 		'menu-item-target'        => '',
 		'menu-item-classes'       => '',
-		'menu-item-content'       => '',
 		'menu-item-xfn'           => '',
 		'menu-item-status'        => '',
 		'menu-item-post-date'     => '',
@@ -574,7 +572,6 @@ function wp_update_nav_menu_item( $menu_id = 0, $menu_item_db_id = 0, $menu_item
 	update_post_meta( $menu_item_db_id, '_menu_item_classes', $args['menu-item-classes'] );
 	update_post_meta( $menu_item_db_id, '_menu_item_xfn', $args['menu-item-xfn'] );
 	update_post_meta( $menu_item_db_id, '_menu_item_url', esc_url_raw( $args['menu-item-url'] ) );
-	update_post_meta( $menu_item_db_id, '_menu_item_content', $args['menu-item-content'] );
 
 	if ( 0 == $menu_id ) {
 		update_post_meta( $menu_item_db_id, '_menu_item_orphaned', (string) time() );
@@ -913,10 +910,6 @@ function wp_setup_nav_menu_item( $menu_item ) {
 
 				$menu_item->title = ( '' === $menu_item->post_title ) ? $original_title : $menu_item->post_title;
 
-			} elseif ( 'block' === $menu_item->type ) {
-				$menu_item->type_label        = __( 'Block' );
-				$menu_item->title             = $menu_item->post_title;
-				$menu_item->menu_item_content = ! isset( $menu_item->menu_item_content ) ? get_post_meta( $menu_item->ID, '_menu_item_content', true ) : $menu_item->menu_item_content;
 			} else {
 				$menu_item->type_label = __( 'Custom Link' );
 				$menu_item->title      = $menu_item->post_title;
diff --git a/wp-includes/rest-api/endpoints/class-wp-rest-menu-items-controller.php b/wp-includes/rest-api/endpoints/class-wp-rest-menu-items-controller.php
index a461a937e5..7a96e0a425 100644
--- a/wp-includes/rest-api/endpoints/class-wp-rest-menu-items-controller.php
+++ b/wp-includes/rest-api/endpoints/class-wp-rest-menu-items-controller.php
@@ -339,7 +339,6 @@ class WP_REST_Menu_Items_Controller extends WP_REST_Posts_Controller {
 				'menu-item-title'       => $menu_item_obj->title,
 				'menu-item-url'         => $menu_item_obj->url,
 				'menu-item-description' => $menu_item_obj->description,
-				'menu-item-content'     => $menu_item_obj->menu_item_content,
 				'menu-item-attr-title'  => $menu_item_obj->attr_title,
 				'menu-item-target'      => $menu_item_obj->target,
 				'menu-item-classes'     => $menu_item_obj->classes,
@@ -360,7 +359,6 @@ class WP_REST_Menu_Items_Controller extends WP_REST_Posts_Controller {
 				'menu-item-title'       => '',
 				'menu-item-url'         => '',
 				'menu-item-description' => '',
-				'menu-item-content'     => '',
 				'menu-item-attr-title'  => '',
 				'menu-item-target'      => '',
 				'menu-item-classes'     => array(),
@@ -409,15 +407,6 @@ class WP_REST_Menu_Items_Controller extends WP_REST_Posts_Controller {
 			}
 		}
 
-		// Nav menu content.
-		if ( ! empty( $schema['properties']['content'] ) && isset( $request['content'] ) ) {
-			if ( is_string( $request['content'] ) ) {
-				$prepared_nav_item['menu-item-content'] = $request['content'];
-			} elseif ( isset( $request['content']['raw'] ) ) {
-				$prepared_nav_item['menu-item-content'] = $request['content']['raw'];
-			}
-		}
-
 		$error = new WP_Error();
 
 		// Check if object id exists before saving.
@@ -460,11 +449,6 @@ class WP_REST_Menu_Items_Controller extends WP_REST_Posts_Controller {
 			}
 		}
 
-		// If menu item is type block, then content is required.
-		if ( 'block' === $prepared_nav_item['menu-item-type'] && empty( $prepared_nav_item['menu-item-content'] ) ) {
-			$error->add( 'rest_content_required', __( 'The content is required when using a block menu item type.' ), array( 'status' => 400 ) );
-		}
-
 		if ( $error->has_errors() ) {
 			return $error;
 		}
@@ -566,23 +550,6 @@ class WP_REST_Menu_Items_Controller extends WP_REST_Posts_Controller {
 			$data['object_id'] = absint( $menu_item->object_id );
 		}
 
-		if ( rest_is_field_included( 'content', $fields ) ) {
-			$data['content'] = array();
-		}
-
-		if ( rest_is_field_included( 'content.raw', $fields ) ) {
-			$data['content']['raw'] = $menu_item->menu_item_content;
-		}
-
-		if ( rest_is_field_included( 'content.rendered', $fields ) ) {
-			/** This filter is documented in wp-includes/post-template.php */
-			$data['content']['rendered'] = apply_filters( 'the_content', $menu_item->menu_item_content );
-		}
-
-		if ( rest_is_field_included( 'content.block_version', $fields ) ) {
-			$data['content']['block_version'] = block_version( $menu_item->menu_item_content );
-		}
-
 		if ( rest_is_field_included( 'parent', $fields ) ) {
 			// Same as post_parent, exposed as an integer.
 			$data['parent'] = (int) $menu_item->menu_item_parent;
@@ -781,7 +748,7 @@ class WP_REST_Menu_Items_Controller extends WP_REST_Posts_Controller {
 		$schema['properties']['type'] = array(
 			'description' => __( 'The family of objects originally represented, such as "post_type" or "taxonomy".' ),
 			'type'        => 'string',
-			'enum'        => array( 'taxonomy', 'post_type', 'post_type_archive', 'custom', 'block' ),
+			'enum'        => array( 'taxonomy', 'post_type', 'post_type_archive', 'custom' ),
 			'context'     => array( 'view', 'edit', 'embed' ),
 			'default'     => 'custom',
 		);
@@ -859,31 +826,6 @@ class WP_REST_Menu_Items_Controller extends WP_REST_Posts_Controller {
 			'default'     => 0,
 		);
 
-		$schema['properties']['content'] = array(
-			'description' => __( 'HTML content to display for this block menu item.' ),
-			'context'     => array( 'view', 'edit', 'embed' ),
-			'type'        => array( 'string', 'object' ),
-			'properties'  => array(
-				'raw'           => array(
-					'description' => __( 'HTML content, as it exists in the database.' ),
-					'type'        => 'string',
-					'context'     => array( 'edit' ),
-				),
-				'rendered'      => array(
-					'description' => __( 'HTML content, transformed for display.' ),
-					'type'        => 'string',
-					'context'     => array( 'view', 'edit' ),
-					'readonly'    => true,
-				),
-				'block_version' => array(
-					'description' => __( 'Version of the block format used in the HTML content.' ),
-					'type'        => 'integer',
-					'context'     => array( 'edit' ),
-					'readonly'    => true,
-				),
-			),
-		);
-
 		$schema['properties']['target'] = array(
 			'description' => __( 'The target attribute of the link element for this menu item.' ),
 			'type'        => 'string',
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 34c8ecfb1f..b48a2a638a 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.9-alpha-52183';
+$wp_version = '5.9-alpha-52184';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.