add_filter( 'woocommerce_is_sold_individually', 'disable_event_sold_individually', 100, 2 );

function disable_event_sold_individually( $return, $product ) {
    // Optional: Only apply this to events if they have a specific category or type
     if ( has_term( 'events', 'product_cat', $product->get_id() ) ) {
       return false;
    }
    return false; // This disables it for everything
}