As far as we know, Chester will maintain the CAF trains along with Machynlleth (which is relatively small).
I think a multi-storey was mooted for the east car park, but instead the developers built a commercial office block and the railway got the remaining space for a modernised ground-level car park.
I don't know what NR got out of it, they certainly owned a slice of the land.
From a paying public point of view, the car park seems to have too many staff cars parked there, but I'm sure the right balance is difficult to strike.
The station area is very congested, with the hotels and increasing amounts of bijou residences being built nearby (eg along the canal route, and the old bus depot).