8.3.0.6.5 Weather Monitoring
Whilst en-route, flight crew are required to monitor the current and forecasted weather conditions at the planned destination, the destination alternate, and any required en-route alternates.
Couldn't be any clearer.
Applied in coordination with the FCOM recommendations you get any weather you feel you need via the appropriate channels.
ED wasn't ever a long-haul commander and never flew outside the USA... therefore I would take any of his previous advice with a pinch of salt.
