apply_filters ( 'jetpack_relatedposts_filter_enabled_for_request', bool $enabled )

Notes

Related Posts aren’t enabled on Pages by default. You can, however, use this filter to change that. Here is how to use it:

function jeherve_allow_pages_for_relatedposts( $enabled ) {
	if ( is_page() ) {
		$enabled = true;
	}
	return $enabled;
}        
add_filter( 'jetpack_relatedposts_filter_enabled_for_request', 'jeherve_allow_pages_for_relatedposts' );