Apart from the two HAS that are now used for Q, the Lossie northern HAS site is not in use That still leaves loads of space for two Typhoon units and the P8s, Charlie & Delta Hards are also plenty big enough as is proven during JW exercises. But I do agree there isn't much room left for the Ops Support & Sqn HQs unless they flatten some of the current buildings, eg the old Engine facility building.
I reckon the other concern is where are all the new staff going to be housed, by my reckoning in the order of a conservative 1000 additional aircrew & groundies need to be found places to work on base and of course families housed.