I'm staggered by that video of what lorry drivers can't see.
How can anything with visibility that bad be allowed on the roads?
It's an articulated lorry. Unfortunately that happens, and those of us who drive, or have driven, them [should] realise and make every attempt to make sure the near side is clear before and during the turn. Visibility in the mirrors is actually very good until the tractor unit starts to turn relative to the trailer, and the cyclists in the video could only have been missed in the mirrors if they all decided to undertake the lorry after it had already started the left turn.
It is the same problem with cars pulling trailers or caravans. Even in a solo car there are areas where the mirrors cannot cover, and the driver cannot see at every moment of a manoeuver.
Perhaps a solution, for the truck driver's view, is to have cameras covering every corner in every direction. However, that would mean that the driver never moves off because the hazards in every view changes every time he/she/ looks at the mirror or video screen.
Ultimately it should be down to a mutual level of respect and consideration between all road users, and driving/riding defensively so as not to trust one's own safety, and the safety of others, to the actions, or lack of, of another road user.