Filter Jetpack widget visibility page list - include all pages, not just those which are published.

functions.php

<?php
/**
 * Filter Jetpack widget visibility page list - include all pages, not just those which are published.
 *
 * @param stdClass[] $pages       Array of objects containing only the ID, post_parent, and post_title fields.
 * @param array      $parsed_args Array of get_pages() arguments.
 */
function iweb_jetpack_widget_visibility_get_pages( $pages, $parsed_args ) {
	global $wpdb;

	$last_changed = wp_cache_get_last_changed( 'posts' );
	$cache_key    = "iweb_get_pages:$last_changed";
	$pages        = wp_cache_get( $cache_key, 'widget_conditions' );
	if ( false === $pages ) {
		$pages = $wpdb->get_results( "SELECT {$wpdb->posts}.ID, {$wpdb->posts}.post_parent, {$wpdb->posts}.post_title FROM {$wpdb->posts} WHERE {$wpdb->posts}.post_type = 'page' AND ({$wpdb->posts}.post_status = 'publish' OR technics_posts.post_status = 'future' OR technics_posts.post_status = 'draft' OR technics_posts.post_status = 'pending' OR technics_posts.post_status = 'private') ORDER BY {$wpdb->posts}.post_title ASC" );
		wp_cache_set( $cache_key, $pages, 'widget_conditions' );
	}

	return $pages;
}
add_filter( 'jetpack_widget_visibility_get_pages', 'iweb_jetpack_widget_visibility_get_pages', 10, 2 );