bristolflyer,
Welcome to PPRuNe.
Having had another look at the master plan I have to agree that the drawing on page 99 of the web version does show airbridges joined to aircraft parked at right-angles to the other nose-in aircraft which don't have any bridges shown.
I had looked at the drawing on web page 76 which accompanies the section on the terminal building expansion plans and which shows extensions of the pier, but no aircraft drawn in (unlike page 99), and assumed these were a means of getting pax a bit closer to the aircraft, albeit they would still have to board via steps.
My assumption was based on the accompanying narrative on page 75 which states, "...........development of a two-level pier between the airport building and the aircraft stands." There is no mention of air bridges anywhere in the plan that I can find, apart from what appears in the drawing on page 99, although I haven't had time for a full re-read following your post.
I was aware of the earlier planning edict concerning air bridges from the current terminal. It may be that, because the three air bridges shown in the above drawing would be parallel with the front of the airside terminal and wouldn't involve a full second floor being built, the airport believes the planners would accept them.
I don't like air bridges and I like the fresh air and an external look at the aircraft that steps provide, in the same way that I prefer narrow-bodied aircraft to wide-bodied for long-haul because there is a great statistical chance of bagging a window seat in the former. I realise I am in the minority in both these matters though.