Does the avoidance of thrust reverser save fuel?
Without further knowledge of the procedures/state of the (a) airport, (b) airline and (c) aircraft , I don't think any conclusive answer could be made. To throw some thoughts in:


All of Kuala Lumpurs's runways are over 4000 meters long, and braking an A320 (at landing weight) can easily be done without thrust reversers over that distance.
Depending where the gate was, they may simply have wanted use more of the runway to speed up the taxi, in which case excessive braking would have been undesirable. Most standard procedures call for a minimum of idle reverse thrust however.
The thrust reversers may have been inoperable, i.e. broken. You are allowed to fly an A320 in that state.




Update: Since you said you didn't sense any thrust reversers (vibration/sound, i.e. no visual confirmation), here's a video to show that they can be pretty quiet even if the doors are opened. If you follow the spiral painted on the spinner note the speed doesn't appear to change a lot even after the plane leaves the runway and the reverser doors are closed.

(Touchdown at 6:50)