I think this is the right move and money well spent, TUDM existing base in KL is worth so much and can bring so much more benefit to the rakyat and country when it turns into commercial use. If they are still occupying that space they are  really "blocking the earth turning".  
Besides, RM20b development is also good for BSS.     

Wonder what the regulations to operate airport or air base near by residential area, among the 8 airbase two located in Subang and Kajang both also got a lot of people live there, how to stand the fighter jet noise and smell of fuel....How many KM are buffer zone leh

Lucky otherwise Kajang is not that big, everyday experience the noise of fighter jets.
Mind to share where is RAR located.

Wonder how Subang folk react, besides RMAF Air Base (location i'm not sure) there is Royal Malaysia Police Air Wings Base under construction located between Ara Damansara Medical Centre and Petronas Fuel Depot.

Among others the new air wing base will have a five storey office cum hangar building, officer’s mess, multi-function hall, an aircraft storm shelter, transport store and others. Didn't mentioned got runnway or not, I think yes otherwise how to store aircraft.

Unlike KA which is about 7km from BSS residential area eg Hijayu (DOE's requirement is 1km), these air base environment impact is much more greater if fighter jet take off and landing near by Subang residential area, why no one make noise ya?

Off topics a bit:

There are 18 aircrafts and 8 helicopters will be in Royal Malaysia Police Air Wing in Subnag, near by Ara Damansara Medical Centre..
https://en.wikipedia.org/wiki/Royal_Malaysi...e_Air_Wing_Unit

Ya I think RMAF Subang Airbase should be near by Subang Airport.

Royal Artillery Regiment @ Kajang
Air Defence Artillery Regiments are either equipped with :
1) Radar guided anti aircraft artillery such as the Oerlikon 35 mm gun system
2) Man portable Surface to Air missiles such as the Shorts Starburst, the Anza MK II and the Igla missile systems, with an effective slant range of 5,000 metres.
3)The BAe Jernas missile provides effective low level air defence within a slant radius of 8,000 metres.

https://en.wikipedia.org/wiki/Rejimen_Artileri_Diraja

Sendayan Airbase only got Training Academy