GSX and thus its VGDS has no way to know, for each airplane, if Chocks or Parking brakes are used, since they can be custom combination of custom variables each airplane can set differently so, once the condition is satisfied at the airplane config level, for GSX and its VGDS, they are all the same thing: a generic "Parking brake", allowing to use GSX while parked.
This means, regardless if you are using an actual Parking Brake or Chocks, the VGDS will always shows "ON CHOCKS", so this is normal.
The problem of the TS-24 kind, which failed to alternate flash between the Gate Info, the Simbrief ETD and the Chocks message, which are all supposed to be alternate-flashing on the first 3 lines ( since there's no space below in the next lines on that model ), will be fixed in the next update.