I can't understand the ramp issue.
The main apron is the eastern apron which has sixteen parking stands.
The general aviation apron (the western apron) is being moved across the runway to a new area in the south which has been constructed in the winter. This will free up space on the old GA apron that will almost double the number of parking places for commercial airliners. Indeed, some airliners already use part of this ramp space at times.
The airport management is talking about 4.5 million pax this year and 5.5 million the following year. If this does happen they will clearly need more than the original sixteen stands on the eastern apron, hence the clearing of GA to the southside.
From a pax point of view, the one drawback to all these extra travellers is the terminal. Although only four years old, and a delight to use at off-peak times, it can become very crowded in the busy periods, especially the baggage reclaim areas, and IMO the building is in need of extension, which it was designed to be capable of.
Interesting comment from flower about the 320s. I hadn't heard this. When I have been at the airport I have not noticed them needing markedly more runway to get off the ground than say a 737 on a similar route. 320s have been using Bristol for many years. I shall certainly watch this with great interest when I am next out there. In fact, I am off to Berlin on a 319 next week so will have a grandstand seat.