... are worried that people might fall off the back of this bus and get run over by the vehicle behind.
(You have to stay the above in a stereotype joke whiny voice to get the proper effect)
Except that it's not a joke. The only concession to that risk that they might have made (and it's not clear) is that they might have changed the orientation of the staircase so that falling down it does dump you directly onto the rear platform, with the possibility of double your (un)luck and fall onwards onto the road. Apart from that, it may look pretty, but it's still only got one entrance (and hence one pinch point) into the lower deck saloon, so it's not going to improve access when the entire thing is rammed during the rush hour. A multiple entrance double decker might have made more sense, but this?
Looks to me like it has two entrances, it's just that the other one is closed in that picture. Look carefully and you can see it half way along.
As for pinch points - strange how that wasn't an issue when the original Routemasters served the route that I still use. The only "benefits" us customers got from the change to shiny! new! bendy! expensive! buses were fewer seats and a less frequent service. Those must be benefits, because they're the only changes, and TfL said we were better off with 'em.