The following snippet shows how to force some products to not trigger the “New product purchase” event.

function my_prefix_exclude_products_for_new_product_purchase_event( $return = false, $user_id = 0, $requirement_id = 0, $trigger = '', $site_id = 0, $args = array() ) {

    // Check if this is the event we are looking for
    if( $return && $trigger === 'gamipress_wc_new_product_purchase' ) {

        $product_id = $args[0];

        // If this is the product we want to exclude, then don't award to the user this
        if( $product_id === 123 ) {
            return false;
        }

    }

    // Send back our eligibility
    return $return;
}
add_filter( 'user_has_access_to_achievement', 'my_prefix_exclude_products_for_new_product_purchase_event', 10, 6 );