function daki_remove_post_top_posts( $posts, $post_ids, $count ) {
    foreach ( $posts as $k => $post ) {

        // Get the list of categories for that post.
        $categories = wp_get_post_categories(
            $post['post_id'],
            // We only need the category slug here.
            array( 'orderby' => 'name', 'order' => 'ASC', 'fields' => 'slugs' )
        );

        // Does one of those categories use a category with the "uncategorized" slug?
        if ( is_array( $categories ) && ! empty ( $categories ) ) {
            foreach ( $categories as $category ) {
                if ( 'uncategorized' == $category ) {
                    unset( $posts[$k] );
                }
            }
        }

    }

    return $posts;
}
add_filter( 'jetpack_widget_get_top_posts', 'daki_remove_post_top_posts', 10, 3 );