Bernard, you’ve found me out!
Actually, I did read up a bit on Bristol (it was originally referred to as a ‘County Corporate’ if I remember correctly) but I omitted going into that level of detail. So in that respect Bristol now being a Unitary Authority (and ‘Ceremonial County’) means it’s returned to a more historically correct position.
However, how would you imagine this being displayed on screen, given that all other locations used a ‘City, County’ model? Bristol is a rare example of being one in the same, but I would imagine certain viewers would find it odd to have Bristol not followed by the name of any county.