Apologies if I'm mistaken, but I think your diagram covers Side Assist only.
I feel it is a wording thing, as you correctly say all UK high spec cars come with "Lane change system Side Assist, Rear Traffic Alert and exit warning system", and Side Assist is the LED in the wing mirror that gives you an indication that it is safe to change lanes by checking your blind spot using the rear sensors. What it cannot check is what is next to or alongside you, the assumption being that the driver will still look left and right to ensure it is safe.
I've actually read the manual again, and it depends on how you interpret 'parking systems'
"Assisted lane changing uses the same sensors as the lane change system (Side Assist) and the parking systems."
I thought parking systems was just front and rear sensors, they help you park! But really it means Park Assist, as it needs the complete 360 Deg coverage that having 16 sensors gives, instead of just the 8 that come as standard.