Well You can also try by adding action inside.
function after_submission( $entry, $form ) {
$name = $entry[2];
$item = $entry[5];
insert_og_in_head( $name, $item );
add_action( "wp_head", "insert_og_in_head" );
}
add_action( "gform_after_submission", "after_submission", 10, 2 );
function insert_og_in_head( $name = NULL, $item = NULL) {
global $post;
if ( !is_page( 6 ) ) //if it is not a post or a page
return;
echo '<meta property="og:title" content="' . $name . ' lorem opossum dolor"/>';
echo '<meta property="og:description" content="' . $item . ' lorem." />';
echo '<meta property="og:type" content="website"/>';
}