Use Generic Copy Whenever Publishing a Post

Supporto WordPress
2

You can do this by customizing the template that is used to send the WordPress content to Discourse. There is some information about how to do that here: Customize the structure of WP Discourse templates

Adding something like this to your functions.php file should work. Insert whatever html you want to use between the closing and opening php tags.

function your_namespace_publish_format_html() {
	ob_start();
	?>

    <p>Generic content to be published to Discourse with every WordPress post...</p>

	<?php
	$output = ob_get_clean();

	return $output;
}
add_filter( 'discourse_publish_format_html', 'your_namespace_publish_format_html' );