gform_form_trash_link

add_filter( 'gform_form_trash_link', 'your_function_name', 10, 2 );

add_filter( 'gform_form_trash_link', 'rename_trash_link', 10, 2 );
function rename_trash_link( $trash_link, $form_id ){
    $trash_link = str_replace( 'Move to Trash', 'Remove this Form', $trash_link );
    return $trash_link;
}

add_filter( 'gform_form_trash_link', 'prevent_form_deletion', 10, 2 );
function prevent_form_deletion( $trash_link, $form_id ){
    if ( $form_id == 75 ) {
        $trash_link = '<a class="submitdelete" onclick="alert(\'This form cannot be deleted.\');" onkeypress="alert(\'This form cannot be deleted.\')">Remove this Form</a>';
    }
    return $trash_link;
}